1 /*- 2 * Copyright (c) 2011, David E. O'Brien. 3 * Copyright (c) 2009-2011, Juniper Networks, Inc. 4 * Copyright (c) 2015, EMC Corp. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY JUNIPER NETWORKS AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL JUNIPER NETWORKS OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include <sys/cdefs.h> 30 __FBSDID("$FreeBSD$"); 31 32 #include "opt_compat.h" 33 34 #include <sys/param.h> 35 #include <sys/file.h> 36 #include <sys/systm.h> 37 #include <sys/buf.h> 38 #include <sys/condvar.h> 39 #include <sys/conf.h> 40 #include <sys/fcntl.h> 41 #include <sys/ioccom.h> 42 #include <sys/kernel.h> 43 #include <sys/lock.h> 44 #include <sys/malloc.h> 45 #include <sys/module.h> 46 #include <sys/poll.h> 47 #include <sys/proc.h> 48 #include <sys/queue.h> 49 #include <sys/sx.h> 50 #include <sys/syscall.h> 51 #include <sys/sysent.h> 52 #include <sys/sysproto.h> 53 #include <sys/uio.h> 54 55 #if __FreeBSD_version >= 900041 56 #include <sys/capsicum.h> 57 #endif 58 59 #include "filemon.h" 60 61 #if defined(COMPAT_IA32) || defined(COMPAT_FREEBSD32) || defined(COMPAT_ARCH32) 62 #include <compat/freebsd32/freebsd32_syscall.h> 63 #include <compat/freebsd32/freebsd32_proto.h> 64 65 extern struct sysentvec ia32_freebsd_sysvec; 66 #endif 67 68 extern struct sysentvec elf32_freebsd_sysvec; 69 extern struct sysentvec elf64_freebsd_sysvec; 70 71 static d_close_t filemon_close; 72 static d_ioctl_t filemon_ioctl; 73 static d_open_t filemon_open; 74 static int filemon_unload(void); 75 static void filemon_load(void *); 76 77 static struct cdevsw filemon_cdevsw = { 78 .d_version = D_VERSION, 79 .d_close = filemon_close, 80 .d_ioctl = filemon_ioctl, 81 .d_open = filemon_open, 82 .d_name = "filemon", 83 }; 84 85 MALLOC_DECLARE(M_FILEMON); 86 MALLOC_DEFINE(M_FILEMON, "filemon", "File access monitor"); 87 88 struct filemon { 89 TAILQ_ENTRY(filemon) link; /* Link into the in-use list. */ 90 struct sx lock; /* Lock mutex for this filemon. */ 91 struct file *fp; /* Output file pointer. */ 92 struct proc *p; /* The process being monitored. */ 93 char fname1[MAXPATHLEN]; /* Temporary filename buffer. */ 94 char fname2[MAXPATHLEN]; /* Temporary filename buffer. */ 95 char msgbufr[1024]; /* Output message buffer. */ 96 }; 97 98 static TAILQ_HEAD(, filemon) filemons_inuse = TAILQ_HEAD_INITIALIZER(filemons_inuse); 99 static TAILQ_HEAD(, filemon) filemons_free = TAILQ_HEAD_INITIALIZER(filemons_free); 100 static struct sx access_lock; 101 102 static struct cdev *filemon_dev; 103 104 #include "filemon_lock.c" 105 #include "filemon_wrapper.c" 106 107 static void 108 filemon_comment(struct filemon *filemon) 109 { 110 int len; 111 struct timeval now; 112 113 getmicrotime(&now); 114 115 len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), 116 "# filemon version %d\n# Target pid %d\n# Start %ju.%06ju\nV %d\n", 117 FILEMON_VERSION, curproc->p_pid, (uintmax_t)now.tv_sec, 118 (uintmax_t)now.tv_usec, FILEMON_VERSION); 119 120 filemon_output(filemon, filemon->msgbufr, len); 121 } 122 123 static void 124 filemon_dtr(void *data) 125 { 126 struct filemon *filemon = data; 127 128 if (filemon != NULL) { 129 struct file *fp; 130 131 /* Follow same locking order as filemon_pid_check. */ 132 filemon_lock_write(); 133 filemon_filemon_lock(filemon); 134 135 /* Remove from the in-use list. */ 136 TAILQ_REMOVE(&filemons_inuse, filemon, link); 137 138 fp = filemon->fp; 139 filemon->fp = NULL; 140 filemon->p = NULL; 141 142 /* Add to the free list. */ 143 TAILQ_INSERT_TAIL(&filemons_free, filemon, link); 144 145 /* Give up write access. */ 146 filemon_filemon_unlock(filemon); 147 filemon_unlock_write(); 148 149 if (fp != NULL) 150 fdrop(fp, curthread); 151 } 152 } 153 154 static int 155 filemon_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag __unused, 156 struct thread *td) 157 { 158 int error = 0; 159 struct filemon *filemon; 160 struct proc *p; 161 #if __FreeBSD_version >= 900041 162 cap_rights_t rights; 163 #endif 164 165 if ((error = devfs_get_cdevpriv((void **) &filemon)) != 0) 166 return (error); 167 168 filemon_filemon_lock(filemon); 169 170 switch (cmd) { 171 /* Set the output file descriptor. */ 172 case FILEMON_SET_FD: 173 if (filemon->fp != NULL) 174 fdrop(filemon->fp, td); 175 176 error = fget_write(td, *(int *)data, 177 #if __FreeBSD_version >= 900041 178 cap_rights_init(&rights, CAP_PWRITE), 179 #endif 180 &filemon->fp); 181 if (error == 0) 182 /* Write the file header. */ 183 filemon_comment(filemon); 184 break; 185 186 /* Set the monitored process ID. */ 187 case FILEMON_SET_PID: 188 error = pget(*((pid_t *)data), PGET_CANDEBUG | PGET_NOTWEXIT, 189 &p); 190 if (error == 0) { 191 filemon->p = p; 192 PROC_UNLOCK(p); 193 } 194 break; 195 196 default: 197 error = EINVAL; 198 break; 199 } 200 201 filemon_filemon_unlock(filemon); 202 return (error); 203 } 204 205 static int 206 filemon_open(struct cdev *dev, int oflags __unused, int devtype __unused, 207 struct thread *td __unused) 208 { 209 struct filemon *filemon; 210 211 /* Get exclusive write access. */ 212 filemon_lock_write(); 213 214 if ((filemon = TAILQ_FIRST(&filemons_free)) != NULL) 215 TAILQ_REMOVE(&filemons_free, filemon, link); 216 217 /* Give up write access. */ 218 filemon_unlock_write(); 219 220 if (filemon == NULL) { 221 filemon = malloc(sizeof(struct filemon), M_FILEMON, 222 M_WAITOK | M_ZERO); 223 sx_init(&filemon->lock, "filemon"); 224 } 225 226 devfs_set_cdevpriv(filemon, filemon_dtr); 227 228 /* Get exclusive write access. */ 229 filemon_lock_write(); 230 231 /* Add to the in-use list. */ 232 TAILQ_INSERT_TAIL(&filemons_inuse, filemon, link); 233 234 /* Give up write access. */ 235 filemon_unlock_write(); 236 237 return (0); 238 } 239 240 static int 241 filemon_close(struct cdev *dev __unused, int flag __unused, int fmt __unused, 242 struct thread *td __unused) 243 { 244 245 return (0); 246 } 247 248 static void 249 filemon_load(void *dummy __unused) 250 { 251 sx_init(&access_lock, "filemons_inuse"); 252 253 /* Install the syscall wrappers. */ 254 filemon_wrapper_install(); 255 256 filemon_dev = make_dev(&filemon_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666, 257 "filemon"); 258 } 259 260 static int 261 filemon_unload(void) 262 { 263 struct filemon *filemon; 264 int error = 0; 265 266 /* Get exclusive write access. */ 267 filemon_lock_write(); 268 269 if (TAILQ_FIRST(&filemons_inuse) != NULL) 270 error = EBUSY; 271 else { 272 destroy_dev(filemon_dev); 273 274 /* Deinstall the syscall wrappers. */ 275 filemon_wrapper_deinstall(); 276 } 277 278 /* Give up write access. */ 279 filemon_unlock_write(); 280 281 if (error == 0) { 282 /* free() filemon structs free list. */ 283 filemon_lock_write(); 284 while ((filemon = TAILQ_FIRST(&filemons_free)) != NULL) { 285 TAILQ_REMOVE(&filemons_free, filemon, link); 286 sx_destroy(&filemon->lock); 287 free(filemon, M_FILEMON); 288 } 289 filemon_unlock_write(); 290 291 sx_destroy(&access_lock); 292 } 293 294 return (error); 295 } 296 297 static int 298 filemon_modevent(module_t mod __unused, int type, void *data) 299 { 300 int error = 0; 301 302 switch (type) { 303 case MOD_LOAD: 304 filemon_load(data); 305 break; 306 307 case MOD_UNLOAD: 308 error = filemon_unload(); 309 break; 310 311 case MOD_SHUTDOWN: 312 break; 313 314 default: 315 error = EOPNOTSUPP; 316 break; 317 318 } 319 320 return (error); 321 } 322 323 DEV_MODULE(filemon, filemon_modevent, NULL); 324 MODULE_VERSION(filemon, 1); 325