1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2011, David E. O'Brien. 5 * Copyright (c) 2009-2011, Juniper Networks, Inc. 6 * Copyright (c) 2015-2016, EMC Corp. 7 * All rights reserved. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 18 * THIS SOFTWARE IS PROVIDED BY JUNIPER NETWORKS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL JUNIPER NETWORKS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 #include <sys/cdefs.h> 32 __FBSDID("$FreeBSD$"); 33 34 #include <sys/eventhandler.h> 35 #include <sys/filedesc.h> 36 #include <sys/imgact.h> 37 #include <sys/priv.h> 38 #include <sys/sx.h> 39 #include <sys/sysent.h> 40 #include <sys/vnode.h> 41 42 #include <machine/stdarg.h> 43 44 static void filemon_output_event(struct filemon *filemon, const char *fmt, ...) 45 __printflike(2, 3); 46 47 static eventhandler_tag filemon_exec_tag; 48 static eventhandler_tag filemon_exit_tag; 49 static eventhandler_tag filemon_fork_tag; 50 51 static void 52 filemon_output(struct filemon *filemon, char *msg, size_t len) 53 { 54 struct uio auio; 55 struct iovec aiov; 56 int error; 57 58 if (filemon->fp == NULL) 59 return; 60 61 aiov.iov_base = msg; 62 aiov.iov_len = len; 63 auio.uio_iov = &aiov; 64 auio.uio_iovcnt = 1; 65 auio.uio_resid = len; 66 auio.uio_segflg = UIO_SYSSPACE; 67 auio.uio_rw = UIO_WRITE; 68 auio.uio_td = curthread; 69 auio.uio_offset = (off_t) -1; 70 71 if (filemon->fp->f_type == DTYPE_VNODE) 72 bwillwrite(); 73 74 error = fo_write(filemon->fp, &auio, filemon->cred, 0, curthread); 75 if (error != 0 && filemon->error == 0) 76 filemon->error = error; 77 } 78 79 static void 80 filemon_output_event(struct filemon *filemon, const char *fmt, ...) 81 { 82 va_list ap; 83 size_t len; 84 85 va_start(ap, fmt); 86 len = vsnprintf(filemon->msgbufr, sizeof(filemon->msgbufr), fmt, ap); 87 va_end(ap); 88 /* The event is truncated but still worth logging. */ 89 if (len >= sizeof(filemon->msgbufr)) 90 len = sizeof(filemon->msgbufr) - 1; 91 filemon_output(filemon, filemon->msgbufr, len); 92 } 93 94 static int 95 filemon_wrapper_chdir(struct thread *td, struct chdir_args *uap) 96 { 97 int error, ret; 98 struct filemon *filemon; 99 100 if ((ret = sys_chdir(td, uap)) == 0) { 101 if ((filemon = filemon_proc_get(curproc)) != NULL) { 102 if ((error = copyinstr(uap->path, filemon->fname1, 103 sizeof(filemon->fname1), NULL)) != 0) { 104 filemon->error = error; 105 goto copyfail; 106 } 107 108 filemon_output_event(filemon, "C %d %s\n", 109 curproc->p_pid, filemon->fname1); 110 copyfail: 111 filemon_drop(filemon); 112 } 113 } 114 115 return (ret); 116 } 117 118 static void 119 filemon_event_process_exec(void *arg __unused, struct proc *p, 120 struct image_params *imgp) 121 { 122 struct filemon *filemon; 123 124 if ((filemon = filemon_proc_get(p)) != NULL) { 125 filemon_output_event(filemon, "E %d %s\n", 126 p->p_pid, 127 imgp->execpath != NULL ? imgp->execpath : "<unknown>"); 128 129 /* If the credentials changed then cease tracing. */ 130 if (imgp->newcred != NULL && 131 imgp->credential_setid && 132 priv_check_cred(filemon->cred, 133 PRIV_DEBUG_DIFFCRED, 0) != 0) { 134 /* 135 * It may have changed to NULL already, but 136 * will not be re-attached by anything else. 137 */ 138 if (p->p_filemon != NULL) { 139 KASSERT(p->p_filemon == filemon, 140 ("%s: proc %p didn't have expected" 141 " filemon %p", __func__, p, filemon)); 142 filemon_proc_drop(p); 143 } 144 } 145 146 147 filemon_drop(filemon); 148 } 149 } 150 151 static void 152 _filemon_wrapper_openat(struct thread *td, const char *upath, int flags, 153 int fd) 154 { 155 int error; 156 struct file *fp; 157 struct filemon *filemon; 158 char *atpath, *freepath; 159 cap_rights_t rights; 160 161 if ((filemon = filemon_proc_get(curproc)) != NULL) { 162 atpath = ""; 163 freepath = NULL; 164 fp = NULL; 165 166 if ((error = copyinstr(upath, filemon->fname1, 167 sizeof(filemon->fname1), NULL)) != 0) { 168 filemon->error = error; 169 goto copyfail; 170 } 171 172 if (filemon->fname1[0] != '/' && fd != AT_FDCWD) { 173 /* 174 * rats - we cannot do too much about this. 175 * the trace should show a dir we read 176 * recently.. output an A record as a clue 177 * until we can do better. 178 * XXX: This may be able to come out with 179 * the namecache lookup now. 180 */ 181 filemon_output_event(filemon, "A %d %s\n", 182 curproc->p_pid, filemon->fname1); 183 /* 184 * Try to resolve the path from the vnode using the 185 * namecache. It may be inaccurate, but better 186 * than nothing. 187 */ 188 if (getvnode(td, fd, 189 cap_rights_init(&rights, CAP_LOOKUP), &fp) == 0) { 190 vn_fullpath(td, fp->f_vnode, &atpath, 191 &freepath); 192 } 193 } 194 if (flags & O_RDWR) { 195 /* 196 * We'll get the W record below, but need 197 * to also output an R to distinguish from 198 * O_WRONLY. 199 */ 200 filemon_output_event(filemon, "R %d %s%s%s\n", 201 curproc->p_pid, atpath, 202 atpath[0] != '\0' ? "/" : "", filemon->fname1); 203 } 204 205 filemon_output_event(filemon, "%c %d %s%s%s\n", 206 (flags & O_ACCMODE) ? 'W':'R', 207 curproc->p_pid, atpath, 208 atpath[0] != '\0' ? "/" : "", filemon->fname1); 209 copyfail: 210 filemon_drop(filemon); 211 if (fp != NULL) 212 fdrop(fp, td); 213 free(freepath, M_TEMP); 214 } 215 } 216 217 static int 218 filemon_wrapper_open(struct thread *td, struct open_args *uap) 219 { 220 int ret; 221 222 if ((ret = sys_open(td, uap)) == 0) 223 _filemon_wrapper_openat(td, uap->path, uap->flags, AT_FDCWD); 224 225 return (ret); 226 } 227 228 static int 229 filemon_wrapper_openat(struct thread *td, struct openat_args *uap) 230 { 231 int ret; 232 233 if ((ret = sys_openat(td, uap)) == 0) 234 _filemon_wrapper_openat(td, uap->path, uap->flag, uap->fd); 235 236 return (ret); 237 } 238 239 static int 240 filemon_wrapper_rename(struct thread *td, struct rename_args *uap) 241 { 242 int error, ret; 243 struct filemon *filemon; 244 245 if ((ret = sys_rename(td, uap)) == 0) { 246 if ((filemon = filemon_proc_get(curproc)) != NULL) { 247 if (((error = copyinstr(uap->from, filemon->fname1, 248 sizeof(filemon->fname1), NULL)) != 0) || 249 ((error = copyinstr(uap->to, filemon->fname2, 250 sizeof(filemon->fname2), NULL)) != 0)) { 251 filemon->error = error; 252 goto copyfail; 253 } 254 255 filemon_output_event(filemon, "M %d '%s' '%s'\n", 256 curproc->p_pid, filemon->fname1, filemon->fname2); 257 copyfail: 258 filemon_drop(filemon); 259 } 260 } 261 262 return (ret); 263 } 264 265 static void 266 _filemon_wrapper_link(struct thread *td, const char *upath1, 267 const char *upath2) 268 { 269 struct filemon *filemon; 270 int error; 271 272 if ((filemon = filemon_proc_get(curproc)) != NULL) { 273 if (((error = copyinstr(upath1, filemon->fname1, 274 sizeof(filemon->fname1), NULL)) != 0) || 275 ((error = copyinstr(upath2, filemon->fname2, 276 sizeof(filemon->fname2), NULL)) != 0)) { 277 filemon->error = error; 278 goto copyfail; 279 } 280 281 filemon_output_event(filemon, "L %d '%s' '%s'\n", 282 curproc->p_pid, filemon->fname1, filemon->fname2); 283 copyfail: 284 filemon_drop(filemon); 285 } 286 } 287 288 static int 289 filemon_wrapper_link(struct thread *td, struct link_args *uap) 290 { 291 int ret; 292 293 if ((ret = sys_link(td, uap)) == 0) 294 _filemon_wrapper_link(td, uap->path, uap->link); 295 296 return (ret); 297 } 298 299 static int 300 filemon_wrapper_symlink(struct thread *td, struct symlink_args *uap) 301 { 302 int ret; 303 304 if ((ret = sys_symlink(td, uap)) == 0) 305 _filemon_wrapper_link(td, uap->path, uap->link); 306 307 return (ret); 308 } 309 310 static int 311 filemon_wrapper_linkat(struct thread *td, struct linkat_args *uap) 312 { 313 int ret; 314 315 if ((ret = sys_linkat(td, uap)) == 0) 316 _filemon_wrapper_link(td, uap->path1, uap->path2); 317 318 return (ret); 319 } 320 321 static void 322 filemon_event_process_exit(void *arg __unused, struct proc *p) 323 { 324 struct filemon *filemon; 325 326 if ((filemon = filemon_proc_get(p)) != NULL) { 327 filemon_output_event(filemon, "X %d %d %d\n", 328 p->p_pid, p->p_xexit, p->p_xsig); 329 330 /* 331 * filemon_untrack_processes() may have dropped this p_filemon 332 * already while in filemon_proc_get() before acquiring the 333 * filemon lock. 334 */ 335 KASSERT(p->p_filemon == NULL || p->p_filemon == filemon, 336 ("%s: p %p was attached while exiting, expected " 337 "filemon %p or NULL", __func__, p, filemon)); 338 if (p->p_filemon == filemon) 339 filemon_proc_drop(p); 340 341 filemon_drop(filemon); 342 } 343 } 344 345 static int 346 filemon_wrapper_unlink(struct thread *td, struct unlink_args *uap) 347 { 348 int error, ret; 349 struct filemon *filemon; 350 351 if ((ret = sys_unlink(td, uap)) == 0) { 352 if ((filemon = filemon_proc_get(curproc)) != NULL) { 353 if ((error = copyinstr(uap->path, filemon->fname1, 354 sizeof(filemon->fname1), NULL)) != 0) { 355 filemon->error = error; 356 goto copyfail; 357 } 358 359 filemon_output_event(filemon, "D %d %s\n", 360 curproc->p_pid, filemon->fname1); 361 copyfail: 362 filemon_drop(filemon); 363 } 364 } 365 366 return (ret); 367 } 368 369 static void 370 filemon_event_process_fork(void *arg __unused, struct proc *p1, 371 struct proc *p2, int flags __unused) 372 { 373 struct filemon *filemon; 374 375 if ((filemon = filemon_proc_get(p1)) != NULL) { 376 filemon_output_event(filemon, "F %d %d\n", 377 p1->p_pid, p2->p_pid); 378 379 /* 380 * filemon_untrack_processes() or 381 * filemon_ioctl(FILEMON_SET_PID) may have changed the parent's 382 * p_filemon while in filemon_proc_get() before acquiring the 383 * filemon lock. Only inherit if the parent is still traced by 384 * this filemon. 385 */ 386 if (p1->p_filemon == filemon) { 387 PROC_LOCK(p2); 388 /* 389 * It may have been attached to already by a new 390 * filemon. 391 */ 392 if (p2->p_filemon == NULL) { 393 p2->p_filemon = filemon_acquire(filemon); 394 ++filemon->proccnt; 395 } 396 PROC_UNLOCK(p2); 397 } 398 399 filemon_drop(filemon); 400 } 401 } 402 403 static void 404 filemon_wrapper_install(void) 405 { 406 407 sysent[SYS_chdir].sy_call = (sy_call_t *) filemon_wrapper_chdir; 408 sysent[SYS_open].sy_call = (sy_call_t *) filemon_wrapper_open; 409 sysent[SYS_openat].sy_call = (sy_call_t *) filemon_wrapper_openat; 410 sysent[SYS_rename].sy_call = (sy_call_t *) filemon_wrapper_rename; 411 sysent[SYS_unlink].sy_call = (sy_call_t *) filemon_wrapper_unlink; 412 sysent[SYS_link].sy_call = (sy_call_t *) filemon_wrapper_link; 413 sysent[SYS_symlink].sy_call = (sy_call_t *) filemon_wrapper_symlink; 414 sysent[SYS_linkat].sy_call = (sy_call_t *) filemon_wrapper_linkat; 415 416 #if defined(COMPAT_FREEBSD32) 417 freebsd32_sysent[FREEBSD32_SYS_chdir].sy_call = (sy_call_t *) filemon_wrapper_chdir; 418 freebsd32_sysent[FREEBSD32_SYS_open].sy_call = (sy_call_t *) filemon_wrapper_open; 419 freebsd32_sysent[FREEBSD32_SYS_openat].sy_call = (sy_call_t *) filemon_wrapper_openat; 420 freebsd32_sysent[FREEBSD32_SYS_rename].sy_call = (sy_call_t *) filemon_wrapper_rename; 421 freebsd32_sysent[FREEBSD32_SYS_unlink].sy_call = (sy_call_t *) filemon_wrapper_unlink; 422 freebsd32_sysent[FREEBSD32_SYS_link].sy_call = (sy_call_t *) filemon_wrapper_link; 423 freebsd32_sysent[FREEBSD32_SYS_symlink].sy_call = (sy_call_t *) filemon_wrapper_symlink; 424 freebsd32_sysent[FREEBSD32_SYS_linkat].sy_call = (sy_call_t *) filemon_wrapper_linkat; 425 #endif /* COMPAT_FREEBSD32 */ 426 427 filemon_exec_tag = EVENTHANDLER_REGISTER(process_exec, 428 filemon_event_process_exec, NULL, EVENTHANDLER_PRI_LAST); 429 filemon_exit_tag = EVENTHANDLER_REGISTER(process_exit, 430 filemon_event_process_exit, NULL, EVENTHANDLER_PRI_LAST); 431 filemon_fork_tag = EVENTHANDLER_REGISTER(process_fork, 432 filemon_event_process_fork, NULL, EVENTHANDLER_PRI_LAST); 433 } 434 435 static void 436 filemon_wrapper_deinstall(void) 437 { 438 439 sysent[SYS_chdir].sy_call = (sy_call_t *)sys_chdir; 440 sysent[SYS_open].sy_call = (sy_call_t *)sys_open; 441 sysent[SYS_openat].sy_call = (sy_call_t *)sys_openat; 442 sysent[SYS_rename].sy_call = (sy_call_t *)sys_rename; 443 sysent[SYS_unlink].sy_call = (sy_call_t *)sys_unlink; 444 sysent[SYS_link].sy_call = (sy_call_t *)sys_link; 445 sysent[SYS_symlink].sy_call = (sy_call_t *)sys_symlink; 446 sysent[SYS_linkat].sy_call = (sy_call_t *)sys_linkat; 447 448 #if defined(COMPAT_FREEBSD32) 449 freebsd32_sysent[FREEBSD32_SYS_chdir].sy_call = (sy_call_t *)sys_chdir; 450 freebsd32_sysent[FREEBSD32_SYS_open].sy_call = (sy_call_t *)sys_open; 451 freebsd32_sysent[FREEBSD32_SYS_openat].sy_call = (sy_call_t *)sys_openat; 452 freebsd32_sysent[FREEBSD32_SYS_rename].sy_call = (sy_call_t *)sys_rename; 453 freebsd32_sysent[FREEBSD32_SYS_unlink].sy_call = (sy_call_t *)sys_unlink; 454 freebsd32_sysent[FREEBSD32_SYS_link].sy_call = (sy_call_t *)sys_link; 455 freebsd32_sysent[FREEBSD32_SYS_symlink].sy_call = (sy_call_t *)sys_symlink; 456 freebsd32_sysent[FREEBSD32_SYS_linkat].sy_call = (sy_call_t *)sys_linkat; 457 #endif /* COMPAT_FREEBSD32 */ 458 459 EVENTHANDLER_DEREGISTER(process_exec, filemon_exec_tag); 460 EVENTHANDLER_DEREGISTER(process_exit, filemon_exit_tag); 461 EVENTHANDLER_DEREGISTER(process_fork, filemon_fork_tag); 462 } 463