1/* $NetBSD: filemon_dev.c,v 1.9 2022/03/04 23:17:16 sjg Exp $ */ 2 3/* 4 * Copyright (c) 2020 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Taylor R. Campbell. 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32#include "filemon.h" 33 34#include <sys/ioctl.h> 35 36#include <errno.h> 37#include <fcntl.h> 38#include <stdlib.h> 39#include <unistd.h> 40 41#ifdef HAVE_FILEMON_H 42# include <filemon.h> 43#endif 44 45#ifndef _PATH_FILEMON 46#define _PATH_FILEMON "/dev/filemon" 47#endif 48 49#ifndef MAKE_ATTR_UNUSED 50#define MAKE_ATTR_UNUSED __attribute__((__unused__)) 51#endif 52 53struct filemon { 54 int fd; 55}; 56 57const char * 58filemon_path(void) 59{ 60 61 return _PATH_FILEMON; 62} 63 64struct filemon * 65filemon_open(void) 66{ 67 struct filemon *F; 68 unsigned i; 69 int error; 70 71 /* Allocate and zero a struct filemon object. */ 72 F = calloc(1, sizeof *F); 73 if (F == NULL) 74 return NULL; 75 76 /* Try opening /dev/filemon, up to six times (cargo cult!). */ 77 for (i = 0; (F->fd = open(_PATH_FILEMON, O_RDWR|O_CLOEXEC)) == -1; i++) { 78 if (i == 5) { 79 error = errno; 80 goto fail0; 81 } 82 } 83 84 /* Success! */ 85 return F; 86 87fail0: free(F); 88 errno = error; 89 return NULL; 90} 91 92int 93filemon_setfd(struct filemon *F, int fd) 94{ 95 96 /* Point the kernel at this file descriptor. */ 97 if (ioctl(F->fd, FILEMON_SET_FD, &fd) == -1) 98 return -1; 99 100 /* No need for it in userland any more; close it. */ 101 (void)close(fd); 102 103 /* Success! */ 104 return 0; 105} 106 107void 108filemon_setpid_parent(struct filemon *F MAKE_ATTR_UNUSED, pid_t pid MAKE_ATTR_UNUSED) 109{ 110 /* Nothing to do! */ 111} 112 113int 114filemon_setpid_child(const struct filemon *F, pid_t pid) 115{ 116 117 /* Just pass it on to the kernel. */ 118 return ioctl(F->fd, FILEMON_SET_PID, &pid); 119} 120 121int 122filemon_close(struct filemon *F) 123{ 124 int error = 0; 125 126 /* Close the filemon device fd. */ 127 if (close(F->fd) == -1 && error == 0) 128 error = errno; 129 130 /* Free the filemon descriptor. */ 131 free(F); 132 133 /* Set errno and return -1 if anything went wrong. */ 134 if (error != 0) { 135 errno = error; 136 return -1; 137 } 138 139 /* Success! */ 140 return 0; 141} 142 143int 144filemon_readfd(const struct filemon *F MAKE_ATTR_UNUSED) 145{ 146 147 return -1; 148} 149 150int 151filemon_process(struct filemon *F MAKE_ATTR_UNUSED) 152{ 153 154 return 0; 155} 156