1 /* 08 Nov 1998*/ 2 /* 3 * cdev.c 4 * 5 * 08 Nov 1998 Rajesh Vaidheeswarran 6 * 7 * Copyright (c) 1998 Rajesh Vaidheeswarran 8 * All rights reserved. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by Rajesh Vaidheeswarran. 21 * 4. The name Rajesh Vaidheeswarran may not be used to endorse or promote 22 * products derived from this software without specific prior written 23 * permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY RAJESH VAIDHEESWARRAN ``AS IS'' AND ANY 26 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE RAJESH VAIDHEESWARRAN BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * Copyright (c) 1993 Terrence R. Lambert. 38 * All rights reserved. 39 * 40 * Redistribution and use in source and binary forms, with or without 41 * modification, are permitted provided that the following conditions 42 * are met: 43 * 1. Redistributions of source code must retain the above copyright 44 * notice, this list of conditions and the following disclaimer. 45 * 2. Redistributions in binary form must reproduce the above copyright 46 * notice, this list of conditions and the following disclaimer in the 47 * documentation and/or other materials provided with the distribution. 48 * 3. All advertising materials mentioning features or use of this software 49 * must display the following acknowledgement: 50 * This product includes software developed by Terrence R. Lambert. 51 * 4. The name Terrence R. Lambert may not be used to endorse or promote 52 * products derived from this software without specific prior written 53 * permission. 54 * 55 * THIS SOFTWARE IS PROVIDED BY TERRENCE R. LAMBERT ``AS IS'' AND ANY 56 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 57 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 58 * ARE DISCLAIMED. IN NO EVENT SHALL THE TERRENCE R. LAMBERT BE LIABLE 59 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 60 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 61 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 62 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 63 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 64 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 65 * SUCH DAMAGE. 66 * 67 * 68 * $FreeBSD: src/share/examples/kld/cdev/module/cdev.c,v 1.3.2.1 2000/10/25 09:02:34 sobomax Exp $ 69 */ 70 #include <sys/types.h> 71 #include <sys/uio.h> 72 #include <sys/param.h> 73 #include <sys/systm.h> 74 #include <sys/ioccom.h> 75 #include <sys/systm.h> 76 #include <sys/conf.h> 77 #include <sys/device.h> 78 79 #include "cdev.h" 80 81 /* 82 * This is the actual code for the system call... it can't be static because 83 * it is exported to another part of the module... the only place it needs 84 * to be referenced is the sysent we are interested in. 85 * 86 * To write your own system call using this as a template, you could strip 87 * out this code and use the rest as a prototype module, changing only the 88 * function names and the number of arguments to the call in the module 89 * specific "sysent". 90 * 91 * You would have to use the "-R" option of "ld" to ensure a linkable file 92 * if you were to do this, since you would need to combine multiple ".o" 93 * files into a single ".o" file for use by "modload". 94 */ 95 96 #define CDEV_IOCTL1 _IOR('C', 1, u_int) 97 98 /* Stores string recv'd by _write() */ 99 static char buf[512+1]; 100 static size_t len; 101 102 int 103 mydev_open(struct dev_open_args *args) 104 { 105 kprintf("mydev_open: dev_t=%d, flags=%x, type=%x\n", 106 devid_from_dev(args->a_head.a_dev), args->a_oflags, 107 args->a_devtype); 108 memset(&buf, '\0', 513); 109 len = 0; 110 111 return (0); 112 } 113 114 int 115 mydev_close(struct dev_close_args *args) 116 { 117 kprintf("mydev_close: dev_t=%d, flags=%x, type=%x\n", 118 devid_from_dev(args->a_head.a_dev), args->a_fflag, 119 args->a_devtype); 120 121 return (0); 122 } 123 124 int 125 mydev_ioctl(struct dev_ioctl_args *args) 126 { 127 int error = 0; 128 129 kprintf("mydev_ioctl: dev_t=%d, cmd=%lx, arg=%p, mode=%x\n", 130 devid_from_dev(args->a_head.a_dev), args->a_cmd, args->a_data, 131 args->a_fflag); 132 133 switch(args->a_cmd) { 134 case CDEV_IOCTL1: 135 kprintf("you called mydev_ioctl CDEV_IOCTL1\n"); 136 break; 137 default: 138 kprintf("No such ioctl for me!\n"); 139 error = EINVAL; 140 break; 141 } 142 143 return (error); 144 } 145 146 /* 147 * mydev_write takes in a character string and saves it 148 * to buf for later accessing. 149 */ 150 int 151 mydev_write(struct dev_write_args *args) 152 { 153 int err = 0; 154 155 kprintf("mydev_write: dev_t=%d, uio=%p, ioflag=%d\n", 156 devid_from_dev(args->a_head.a_dev), args->a_uio, args->a_ioflag); 157 158 err = copyinstr(args->a_uio->uio_iov->iov_base, &buf, 512, &len); 159 if (err != 0) { 160 kprintf("Write to \"cdev\" failed.\n"); 161 } 162 163 return (err); 164 } 165 166 /* 167 * The mydev_read function just takes the buf that was saved 168 * via mydev_write() and returns it to userland for 169 * accessing. 170 */ 171 int 172 mydev_read(struct dev_read_args *args) 173 { 174 int err = 0; 175 176 kprintf("mydev_read: dev_t=%d, uio=%p, ioflag=%d\n", 177 devid_from_dev(args->a_head.a_dev), args->a_uio, args->a_ioflag); 178 179 if (len <= 0) { 180 err = -1; 181 } 182 else { 183 /* copy buf to userland */ 184 copystr(&buf, args->a_uio->uio_iov->iov_base, 513, &len); 185 } 186 187 return (err); 188 } 189