cdev.c revision 86316
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: head/share/examples/kld/cdev/module/cdev.c 86316 2001-11-13 07:42:30Z arr $ 69 */ 70#include <sys/types.h> 71#include <sys/uio.h> 72#include <sys/param.h> 73#include <sys/proc.h> 74#include <sys/systm.h> 75#include <sys/ioccom.h> 76#include <sys/systm.h> 77#include <sys/conf.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() */ 99static char buf[512+1]; 100static int len; 101 102int 103mydev_open(dev_t dev, int flag, int otyp, struct thread *td) 104{ 105 struct proc *procp = td->td_proc; 106 107 printf("mydev_open: dev_t=%d, flag=%x, otyp=%x, procp=%p\n", 108 dev2udev(dev), flag, otyp, procp); 109 memset(&buf, '\0', 513); 110 len = 0; 111 return (0); 112} 113 114int 115mydev_close(dev_t dev, int flag, int otyp, struct thread *td) 116{ 117 struct proc *procp = td->td_proc; 118 119 printf("mydev_close: dev_t=%d, flag=%x, otyp=%x, procp=%p\n", 120 dev2udev(dev), flag, otyp, procp); 121 return (0); 122} 123 124int 125mydev_ioctl(dev_t dev, u_long cmd, caddr_t arg, int mode, struct thread *td) 126{ 127 int error = 0; 128 struct proc *procp = td->td_proc; 129 130 printf("mydev_ioctl: dev_t=%d, cmd=%lx, arg=%p, mode=%x procp=%p\n", 131 dev2udev(dev), cmd, arg, mode, procp); 132 133 switch(cmd) { 134 case CDEV_IOCTL1: 135 printf("you called mydev_ioctl CDEV_IOCTL1\n"); 136 break; 137 default: 138 printf("No such ioctl for me!\n"); 139 error = EINVAL; 140 break; 141 } 142 return error; 143} 144 145/* 146 * mydev_write takes in a character string and saves it 147 * to buf for later accessing. 148 */ 149int 150mydev_write(dev_t dev, struct uio *uio, int ioflag) 151{ 152 int err = 0; 153 154 printf("mydev_write: dev_t=%d, uio=%p, ioflag=%d\n", 155 dev2udev(dev), uio, ioflag); 156 157 err = copyinstr(uio->uio_iov->iov_base, &buf, 512, &len); 158 if (err != 0) { 159 printf("Write to \"cdev\" failed.\n"); 160 } 161 return(err); 162} 163 164/* 165 * The mydev_read function just takes the buf that was saved 166 * via mydev_write() and returns it to userland for 167 * accessing. 168 */ 169int 170mydev_read(dev_t dev, struct uio *uio, int ioflag) 171{ 172 int err = 0; 173 174 printf("mydev_read: dev_t=%d, uio=%p, ioflag=%d\n", 175 dev2udev(dev), uio, ioflag); 176 177 if (len <= 0) { 178 err = -1; 179 } else { /* copy buf to userland */ 180 copystr(&buf, uio->uio_iov->iov_base, 513, &len); 181 } 182 return(err); 183} 184