1 /* 08 Nov 1998*/
2 /*-
3 * cdev.c
4 *
5 * 08 Nov 1998 Rajesh Vaidheeswarran
6 *
7 * SPDX-License-Identifier: BSD-4-Clause
8 *
9 * Copyright (c) 1998 Rajesh Vaidheeswarran
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 * must display the following acknowledgement:
22 * This product includes software developed by Rajesh Vaidheeswarran.
23 * 4. The name Rajesh Vaidheeswarran may not be used to endorse or promote
24 * products derived from this software without specific prior written
25 * permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY RAJESH VAIDHEESWARRAN ``AS IS'' AND ANY
28 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED. IN NO EVENT SHALL THE RAJESH VAIDHEESWARRAN BE LIABLE
31 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
32 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
33 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
34 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
35 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
36 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
37 * SUCH DAMAGE.
38 *
39 * Copyright (c) 1993 Terrence R. Lambert.
40 * All rights reserved.
41 *
42 * Redistribution and use in source and binary forms, with or without
43 * modification, are permitted provided that the following conditions
44 * are met:
45 * 1. Redistributions of source code must retain the above copyright
46 * notice, this list of conditions and the following disclaimer.
47 * 2. Redistributions in binary form must reproduce the above copyright
48 * notice, this list of conditions and the following disclaimer in the
49 * documentation and/or other materials provided with the distribution.
50 * 3. All advertising materials mentioning features or use of this software
51 * must display the following acknowledgement:
52 * This product includes software developed by Terrence R. Lambert.
53 * 4. The name Terrence R. Lambert may not be used to endorse or promote
54 * products derived from this software without specific prior written
55 * permission.
56 *
57 * THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``AS IS'' AND ANY
58 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
59 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
60 * ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE
61 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
62 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
63 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
64 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
65 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
66 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
67 * SUCH DAMAGE.
68 *
69 */
70 #include <sys/param.h>
71 #include <sys/uio.h>
72 #include <sys/proc.h>
73 #include <sys/systm.h>
74 #include <sys/ioccom.h>
75 #include <sys/conf.h>
76
77 #include "cdev.h"
78
79 /*
80 * This is the actual code for the system call... it can't be static because
81 * it is exported to another part of the module... the only place it needs
82 * to be referenced is the sysent we are interested in.
83 *
84 * To write your own system call using this as a template, you could strip
85 * out this code and use the rest as a prototype module, changing only the
86 * function names and the number of arguments to the call in the module
87 * specific "sysent".
88 *
89 * You would have to use the "-R" option of "ld" to ensure a linkable file
90 * if you were to do this, since you would need to combine multiple ".o"
91 * files into a single ".o" file for use by "modload".
92 */
93
94 #define CDEV_IOCTL1 _IOR('C', 1, u_int)
95
96 /* Stores string recv'd by _write() */
97 static char buf[512+1];
98 static size_t len;
99
100 int
mydev_open(struct cdev * dev,int flag,int otyp,struct thread * td)101 mydev_open(struct cdev *dev, int flag, int otyp, struct thread *td)
102 {
103 struct proc *procp = td->td_proc;
104
105 printf("mydev_open: dev_t=%lu, flag=%x, otyp=%x, procp=%p\n",
106 dev2udev(dev), flag, otyp, procp);
107 memset(&buf, '\0', 513);
108 len = 0;
109 return (0);
110 }
111
112 int
mydev_close(struct cdev * dev,int flag,int otyp,struct thread * td)113 mydev_close(struct cdev *dev, int flag, int otyp, struct thread *td)
114 {
115 struct proc *procp = td->td_proc;
116
117 printf("mydev_close: dev_t=%lu, flag=%x, otyp=%x, procp=%p\n",
118 dev2udev(dev), flag, otyp, procp);
119 return (0);
120 }
121
122 int
mydev_ioctl(struct cdev * dev,u_long cmd,caddr_t arg,int mode,struct thread * td)123 mydev_ioctl(struct cdev *dev, u_long cmd, caddr_t arg, int mode,
124 struct thread *td)
125 {
126 int error = 0;
127 struct proc *procp = td->td_proc;
128
129 printf("mydev_ioctl: dev_t=%lu, cmd=%lx, arg=%p, mode=%x procp=%p\n",
130 dev2udev(dev), cmd, arg, mode, procp);
131
132 switch(cmd) {
133 case CDEV_IOCTL1:
134 printf("you called mydev_ioctl CDEV_IOCTL1\n");
135 break;
136 default:
137 printf("No such ioctl for me!\n");
138 error = EINVAL;
139 break;
140 }
141 return (error);
142 }
143
144 /*
145 * mydev_write takes in a character string and saves it
146 * to buf for later accessing.
147 */
148 int
mydev_write(struct cdev * dev,struct uio * uio,int ioflag)149 mydev_write(struct cdev *dev, struct uio *uio, int ioflag)
150 {
151 int err = 0;
152
153 printf("mydev_write: dev_t=%lu, uio=%p, ioflag=%d\n",
154 dev2udev(dev), uio, ioflag);
155
156 err = copyinstr(uio->uio_iov->iov_base, &buf, 512, &len);
157 if (err != 0) {
158 printf("Write to \"cdev\" failed.\n");
159 }
160 return(err);
161 }
162
163 /*
164 * The mydev_read function just takes the buf that was saved
165 * via mydev_write() and returns it to userland for
166 * accessing.
167 */
168 int
mydev_read(struct cdev * dev,struct uio * uio,int ioflag)169 mydev_read(struct cdev *dev, struct uio *uio, int ioflag)
170 {
171 int err = 0;
172
173 printf("mydev_read: dev_t=%lu, uio=%p, ioflag=%d\n",
174 dev2udev(dev), uio, ioflag);
175
176 if (len <= 0) {
177 err = -1;
178 } else { /* copy buf to userland */
179 copystr(&buf, uio->uio_iov->iov_base, 513, &len);
180 }
181 return(err);
182 }
183