Index: head/share/man/man4/filemon.4 =================================================================== --- head/share/man/man4/filemon.4 (revision 297202) +++ head/share/man/man4/filemon.4 (revision 297203) @@ -1,232 +1,241 @@ .\" Copyright (c) 2012 .\" David E. O'Brien . All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgment: .\" This product includes software developed by David E. O'Brien and .\" contributors. .\" 4. Neither the name of the author nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANT ABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" $FreeBSD$ .\" .Dd March 22, 2016 .Dt FILEMON 4 .Os .Sh NAME .Nm filemon .Nd the filemon device .Sh SYNOPSIS .In dev/filemon/filemon.h .Sh DESCRIPTION The .Nm device allows a process to collect file operations data of its children. The device .Pa /dev/filemon responds to two .Xr ioctl 2 calls. .Pp .Nm is not intended to be a security auditing tool. Many system calls are not tracked and binaries of foreign ABI will not be fully audited. It is intended for auditing of processes for the purpose of determining its dependencies in an efficient and easily parsable format. An example of this is .Xr make 1 which uses this module with .Sy .MAKE.MODE=meta to handle incremental builds more smartly. .Pp System calls are denoted using the following single letters: .Pp .Bl -tag -width indent -compact .It Ql A .Xr openat 2 . The next log entry may be lacking an absolute path or be inaccurate. .It Ql C .Xr chdir 2 .It Ql D .Xr unlink 2 .It Ql E .Xr exec 2 .It Ql F .Xr fork 2 , .Xr vfork 2 .It Ql L .Xr link 2 , .Xr linkat 2 , .Xr symlink 2 , .Xr symlinkat 2 .It Ql M .Xr rename 2 .It Ql R .Xr open 2 or .Xr openat 2 for read .It Ql W .Xr open 2 or .Xr openat 2 for write .It Ql X .Xr _exit 2 .El .Pp Note that .Ql R following .Ql W records can represent a single .Xr open 2 for R/W, or two separate .Xr open 2 calls, one for .Ql R and one for .Ql W . Note that only successful system calls are captured. .Sh IOCTLS User mode programs communicate with the .Nm driver through a number of ioctls which are described below. Each takes a single argument. .Bl -tag -width ".Dv FILEMON_SET_PID" .It Dv FILEMON_SET_FD Write the internal tracing buffer to the supplied open file descriptor. .It Dv FILEMON_SET_PID Child process ID to trace. This should normally be done under the control of a parent in the child after .Xr fork 2 but before anything else. See the example below. .El .Sh RETURN VALUES .\" .Rv -std ioctl The .Fn ioctl function returns the value 0 if successful; otherwise the value \-1 is returned and the global variable .Va errno is set to indicate the error. .Sh ERRORS The .Fn ioctl system call with .Dv FILEMON_SET_FD will fail if: .Bl -tag -width Er .It Bq Er EEXIST The .Nm handle is already associated with a file descriptor. .El .Pp The .Fn ioctl system call with .Dv FILEMON_SET_PID will fail if: .Bl -tag -width Er .It Bq Er ESRCH No process having the specified process ID exists. .It Bq Er EBUSY The process ID specified is already being traced and was not the current process. .El .Pp The .Fn close system call on the filemon file descriptor may fail with the errors from .Xr write 2 if any error is encountered while writing the log. +It may also fail if: +.Bl -tag -width Er +.It Bq Er EFAULT +An invalid address was used for a traced system call argument, resulting in +no log entry for the system call. +.It Bq Er ENAMETOOLONG +An argument for a traced system call was too long, resulting in +no log entry for the system call. +.El .Sh FILES .Bl -tag -width ".Pa /dev/filemon" .It Pa /dev/filemon .El .Sh EXAMPLES .Bd -literal #include #include #include #include #include #include #include #include static void open_filemon(void) { pid_t child; int fm_fd, fm_log; if ((fm_fd = open("/dev/filemon", O_RDWR | O_CLOEXEC)) == -1) err(1, "open(\e"/dev/filemon\e", O_RDWR)"); if ((fm_log = open("filemon.out", O_CREAT | O_WRONLY | O_TRUNC | O_CLOEXEC, DEFFILEMODE)) == -1) err(1, "open(filemon.out)"); if (ioctl(fm_fd, FILEMON_SET_FD, &fm_log) == -1) err(1, "Cannot set filemon log file descriptor"); if ((child = fork()) == 0) { child = getpid(); if (ioctl(fm_fd, FILEMON_SET_PID, &child) == -1) err(1, "Cannot set filemon PID"); /* Do something here. */ } else { wait(&child); close(fm_fd); } } .Ed .Pp Creates a file named .Pa filemon.out and configures the .Nm device to write the .Nm buffer contents to it. .Sh SEE ALSO .Xr dtrace 1 , .Xr ktrace 1 , .Xr script 1 , .Xr truss 1 , .Xr ioctl 2 .Sh HISTORY A .Nm device appeared in .Fx 9.1 . .Sh BUGS Unloading the module may panic the system, thus requires using .Ic kldunload -f . Index: head/sys/dev/filemon/filemon_wrapper.c =================================================================== --- head/sys/dev/filemon/filemon_wrapper.c (revision 297202) +++ head/sys/dev/filemon/filemon_wrapper.c (revision 297203) @@ -1,458 +1,475 @@ /*- * Copyright (c) 2011, David E. O'Brien. * Copyright (c) 2009-2011, Juniper Networks, Inc. * Copyright (c) 2015-2016, EMC Corp. * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY JUNIPER NETWORKS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL JUNIPER NETWORKS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #include __FBSDID("$FreeBSD$"); #include #include #include #include #include #include "opt_compat.h" static eventhandler_tag filemon_exec_tag; static eventhandler_tag filemon_exit_tag; static eventhandler_tag filemon_fork_tag; static void filemon_output(struct filemon *filemon, char *msg, size_t len) { struct uio auio; struct iovec aiov; int error; if (filemon->fp == NULL) return; aiov.iov_base = msg; aiov.iov_len = len; auio.uio_iov = &aiov; auio.uio_iovcnt = 1; auio.uio_resid = len; auio.uio_segflg = UIO_SYSSPACE; auio.uio_rw = UIO_WRITE; auio.uio_td = curthread; auio.uio_offset = (off_t) -1; if (filemon->fp->f_type == DTYPE_VNODE) bwillwrite(); error = fo_write(filemon->fp, &auio, curthread->td_ucred, 0, curthread); if (error != 0) filemon->error = error; } static int filemon_wrapper_chdir(struct thread *td, struct chdir_args *uap) { - int ret; + int error, ret; size_t len; struct filemon *filemon; if ((ret = sys_chdir(td, uap)) == 0) { if ((filemon = filemon_proc_get(curproc)) != NULL) { - copyinstr(uap->path, filemon->fname1, - sizeof(filemon->fname1), NULL); + if ((error = copyinstr(uap->path, filemon->fname1, + sizeof(filemon->fname1), NULL)) != 0) { + filemon->error = error; + goto copyfail; + } len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "C %d %s\n", curproc->p_pid, filemon->fname1); filemon_output(filemon, filemon->msgbufr, len); - +copyfail: filemon_drop(filemon); } } return (ret); } static void filemon_event_process_exec(void *arg __unused, struct proc *p, struct image_params *imgp) { struct filemon *filemon; char *fullpath, *freepath; size_t len; if ((filemon = filemon_proc_get(p)) != NULL) { fullpath = ""; freepath = NULL; vn_fullpath(curthread, imgp->vp, &fullpath, &freepath); len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "E %d %s\n", p->p_pid, fullpath); filemon_output(filemon, filemon->msgbufr, len); filemon_drop(filemon); free(freepath, M_TEMP); } } static void _filemon_wrapper_openat(struct thread *td, char *upath, int flags, int fd) { + int error; size_t len; struct file *fp; struct filemon *filemon; char *atpath, *freepath; cap_rights_t rights; if ((filemon = filemon_proc_get(curproc)) != NULL) { atpath = ""; freepath = NULL; fp = NULL; - copyinstr(upath, filemon->fname1, - sizeof(filemon->fname1), NULL); + if ((error = copyinstr(upath, filemon->fname1, + sizeof(filemon->fname1), NULL)) != 0) { + filemon->error = error; + goto copyfail; + } if (filemon->fname1[0] != '/' && fd != AT_FDCWD) { /* * rats - we cannot do too much about this. * the trace should show a dir we read * recently.. output an A record as a clue * until we can do better. * XXX: This may be able to come out with * the namecache lookup now. */ len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "A %d %s\n", curproc->p_pid, filemon->fname1); filemon_output(filemon, filemon->msgbufr, len); /* * Try to resolve the path from the vnode using the * namecache. It may be inaccurate, but better * than nothing. */ if (getvnode(td, fd, cap_rights_init(&rights, CAP_LOOKUP), &fp) == 0) { vn_fullpath(td, fp->f_vnode, &atpath, &freepath); } } if (flags & O_RDWR) { /* * We'll get the W record below, but need * to also output an R to distinguish from * O_WRONLY. */ len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "R %d %s%s%s\n", curproc->p_pid, atpath, atpath[0] != '\0' ? "/" : "", filemon->fname1); filemon_output(filemon, filemon->msgbufr, len); } len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "%c %d %s%s%s\n", (flags & O_ACCMODE) ? 'W':'R', curproc->p_pid, atpath, atpath[0] != '\0' ? "/" : "", filemon->fname1); filemon_output(filemon, filemon->msgbufr, len); - +copyfail: filemon_drop(filemon); if (fp != NULL) fdrop(fp, td); free(freepath, M_TEMP); } } static int filemon_wrapper_open(struct thread *td, struct open_args *uap) { int ret; if ((ret = sys_open(td, uap)) == 0) _filemon_wrapper_openat(td, uap->path, uap->flags, AT_FDCWD); return (ret); } static int filemon_wrapper_openat(struct thread *td, struct openat_args *uap) { int ret; if ((ret = sys_openat(td, uap)) == 0) _filemon_wrapper_openat(td, uap->path, uap->flag, uap->fd); return (ret); } static int filemon_wrapper_rename(struct thread *td, struct rename_args *uap) { - int ret; + int error, ret; size_t len; struct filemon *filemon; if ((ret = sys_rename(td, uap)) == 0) { if ((filemon = filemon_proc_get(curproc)) != NULL) { - copyinstr(uap->from, filemon->fname1, - sizeof(filemon->fname1), NULL); - copyinstr(uap->to, filemon->fname2, - sizeof(filemon->fname2), NULL); + if (((error = copyinstr(uap->from, filemon->fname1, + sizeof(filemon->fname1), NULL)) != 0) || + ((error = copyinstr(uap->to, filemon->fname2, + sizeof(filemon->fname2), NULL)) != 0)) { + filemon->error = error; + goto copyfail; + } len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "M %d '%s' '%s'\n", curproc->p_pid, filemon->fname1, filemon->fname2); filemon_output(filemon, filemon->msgbufr, len); - +copyfail: filemon_drop(filemon); } } return (ret); } static void _filemon_wrapper_link(struct thread *td, char *upath1, char *upath2) { struct filemon *filemon; size_t len; + int error; if ((filemon = filemon_proc_get(curproc)) != NULL) { - copyinstr(upath1, filemon->fname1, - sizeof(filemon->fname1), NULL); - copyinstr(upath2, filemon->fname2, - sizeof(filemon->fname2), NULL); + if (((error = copyinstr(upath1, filemon->fname1, + sizeof(filemon->fname1), NULL)) != 0) || + ((error = copyinstr(upath2, filemon->fname2, + sizeof(filemon->fname2), NULL)) != 0)) { + filemon->error = error; + goto copyfail; + } len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "L %d '%s' '%s'\n", curproc->p_pid, filemon->fname1, filemon->fname2); filemon_output(filemon, filemon->msgbufr, len); - +copyfail: filemon_drop(filemon); } } static int filemon_wrapper_link(struct thread *td, struct link_args *uap) { int ret; if ((ret = sys_link(td, uap)) == 0) _filemon_wrapper_link(td, uap->path, uap->link); return (ret); } static int filemon_wrapper_symlink(struct thread *td, struct symlink_args *uap) { int ret; if ((ret = sys_symlink(td, uap)) == 0) _filemon_wrapper_link(td, uap->path, uap->link); return (ret); } static int filemon_wrapper_linkat(struct thread *td, struct linkat_args *uap) { int ret; if ((ret = sys_linkat(td, uap)) == 0) _filemon_wrapper_link(td, uap->path1, uap->path2); return (ret); } static void filemon_event_process_exit(void *arg __unused, struct proc *p) { size_t len; struct filemon *filemon; if ((filemon = filemon_proc_get(p)) != NULL) { len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "X %d %d %d\n", p->p_pid, p->p_xexit, p->p_xsig); filemon_output(filemon, filemon->msgbufr, len); /* * filemon_untrack_processes() may have dropped this p_filemon * already while in filemon_proc_get() before acquiring the * filemon lock. */ KASSERT(p->p_filemon == NULL || p->p_filemon == filemon, ("%s: p %p was attached while exiting, expected " "filemon %p or NULL", __func__, p, filemon)); if (p->p_filemon == filemon) filemon_proc_drop(p); filemon_drop(filemon); } } static int filemon_wrapper_unlink(struct thread *td, struct unlink_args *uap) { - int ret; + int error, ret; size_t len; struct filemon *filemon; if ((ret = sys_unlink(td, uap)) == 0) { if ((filemon = filemon_proc_get(curproc)) != NULL) { - copyinstr(uap->path, filemon->fname1, - sizeof(filemon->fname1), NULL); + if ((error = copyinstr(uap->path, filemon->fname1, + sizeof(filemon->fname1), NULL)) != 0) { + filemon->error = error; + goto copyfail; + } len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "D %d %s\n", curproc->p_pid, filemon->fname1); filemon_output(filemon, filemon->msgbufr, len); - +copyfail: filemon_drop(filemon); } } return (ret); } static void filemon_event_process_fork(void *arg __unused, struct proc *p1, struct proc *p2, int flags __unused) { size_t len; struct filemon *filemon; if ((filemon = filemon_proc_get(p1)) != NULL) { len = snprintf(filemon->msgbufr, sizeof(filemon->msgbufr), "F %d %d\n", p1->p_pid, p2->p_pid); filemon_output(filemon, filemon->msgbufr, len); /* * filemon_untrack_processes() or * filemon_ioctl(FILEMON_SET_PID) may have changed the parent's * p_filemon while in filemon_proc_get() before acquiring the * filemon lock. Only inherit if the parent is still traced by * this filemon. */ if (p1->p_filemon == filemon) { PROC_LOCK(p2); /* * It may have been attached to already by a new * filemon. */ if (p2->p_filemon == NULL) { p2->p_filemon = filemon_acquire(filemon); ++filemon->proccnt; } PROC_UNLOCK(p2); } filemon_drop(filemon); } } static void filemon_wrapper_install(void) { #if defined(__LP64__) struct sysent *sv_table = elf64_freebsd_sysvec.sv_table; #else struct sysent *sv_table = elf32_freebsd_sysvec.sv_table; #endif sv_table[SYS_chdir].sy_call = (sy_call_t *) filemon_wrapper_chdir; sv_table[SYS_open].sy_call = (sy_call_t *) filemon_wrapper_open; sv_table[SYS_openat].sy_call = (sy_call_t *) filemon_wrapper_openat; sv_table[SYS_rename].sy_call = (sy_call_t *) filemon_wrapper_rename; sv_table[SYS_unlink].sy_call = (sy_call_t *) filemon_wrapper_unlink; sv_table[SYS_link].sy_call = (sy_call_t *) filemon_wrapper_link; sv_table[SYS_symlink].sy_call = (sy_call_t *) filemon_wrapper_symlink; sv_table[SYS_linkat].sy_call = (sy_call_t *) filemon_wrapper_linkat; #if defined(COMPAT_IA32) || defined(COMPAT_FREEBSD32) || defined(COMPAT_ARCH32) sv_table = ia32_freebsd_sysvec.sv_table; sv_table[FREEBSD32_SYS_chdir].sy_call = (sy_call_t *) filemon_wrapper_chdir; sv_table[FREEBSD32_SYS_open].sy_call = (sy_call_t *) filemon_wrapper_open; sv_table[FREEBSD32_SYS_openat].sy_call = (sy_call_t *) filemon_wrapper_openat; sv_table[FREEBSD32_SYS_rename].sy_call = (sy_call_t *) filemon_wrapper_rename; sv_table[FREEBSD32_SYS_unlink].sy_call = (sy_call_t *) filemon_wrapper_unlink; sv_table[FREEBSD32_SYS_link].sy_call = (sy_call_t *) filemon_wrapper_link; sv_table[FREEBSD32_SYS_symlink].sy_call = (sy_call_t *) filemon_wrapper_symlink; sv_table[FREEBSD32_SYS_linkat].sy_call = (sy_call_t *) filemon_wrapper_linkat; #endif /* COMPAT_ARCH32 */ filemon_exec_tag = EVENTHANDLER_REGISTER(process_exec, filemon_event_process_exec, NULL, EVENTHANDLER_PRI_LAST); filemon_exit_tag = EVENTHANDLER_REGISTER(process_exit, filemon_event_process_exit, NULL, EVENTHANDLER_PRI_LAST); filemon_fork_tag = EVENTHANDLER_REGISTER(process_fork, filemon_event_process_fork, NULL, EVENTHANDLER_PRI_LAST); } static void filemon_wrapper_deinstall(void) { #if defined(__LP64__) struct sysent *sv_table = elf64_freebsd_sysvec.sv_table; #else struct sysent *sv_table = elf32_freebsd_sysvec.sv_table; #endif sv_table[SYS_chdir].sy_call = (sy_call_t *)sys_chdir; sv_table[SYS_open].sy_call = (sy_call_t *)sys_open; sv_table[SYS_openat].sy_call = (sy_call_t *)sys_openat; sv_table[SYS_rename].sy_call = (sy_call_t *)sys_rename; sv_table[SYS_unlink].sy_call = (sy_call_t *)sys_unlink; sv_table[SYS_link].sy_call = (sy_call_t *)sys_link; sv_table[SYS_symlink].sy_call = (sy_call_t *)sys_symlink; sv_table[SYS_linkat].sy_call = (sy_call_t *)sys_linkat; #if defined(COMPAT_IA32) || defined(COMPAT_FREEBSD32) || defined(COMPAT_ARCH32) sv_table = ia32_freebsd_sysvec.sv_table; sv_table[FREEBSD32_SYS_chdir].sy_call = (sy_call_t *)sys_chdir; sv_table[FREEBSD32_SYS_open].sy_call = (sy_call_t *)sys_open; sv_table[FREEBSD32_SYS_openat].sy_call = (sy_call_t *)sys_openat; sv_table[FREEBSD32_SYS_rename].sy_call = (sy_call_t *)sys_rename; sv_table[FREEBSD32_SYS_unlink].sy_call = (sy_call_t *)sys_unlink; sv_table[FREEBSD32_SYS_link].sy_call = (sy_call_t *)sys_link; sv_table[FREEBSD32_SYS_symlink].sy_call = (sy_call_t *)sys_symlink; sv_table[FREEBSD32_SYS_linkat].sy_call = (sy_call_t *)sys_linkat; #endif /* COMPAT_ARCH32 */ EVENTHANDLER_DEREGISTER(process_exec, filemon_exec_tag); EVENTHANDLER_DEREGISTER(process_exit, filemon_exit_tag); EVENTHANDLER_DEREGISTER(process_fork, filemon_fork_tag); }