2 * Copyright (c) 2011, David E. O'Brien.
3 * Copyright (c) 2009-2011, Juniper Networks, Inc.
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
15 * THIS SOFTWARE IS PROVIDED BY JUNIPER NETWORKS AND CONTRIBUTORS ``AS IS'' AND
16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18 * ARE DISCLAIMED. IN NO EVENT SHALL JUNIPER NETWORKS OR CONTRIBUTORS BE LIABLE
19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 #include <sys/cdefs.h>
29 __FBSDID("$FreeBSD$");
31 #include "opt_compat.h"
33 #include <sys/param.h>
35 #include <sys/systm.h>
37 #include <sys/condvar.h>
39 #include <sys/fcntl.h>
40 #include <sys/ioccom.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/module.h>
44 #include <sys/mutex.h>
47 #include <sys/queue.h>
48 #include <sys/syscall.h>
49 #include <sys/sysent.h>
50 #include <sys/sysproto.h>
53 #if __FreeBSD_version >= 900041
54 #include <sys/capability.h>
59 #if defined(COMPAT_IA32) || defined(COMPAT_FREEBSD32) || defined(COMPAT_ARCH32)
60 #include <compat/freebsd32/freebsd32_syscall.h>
61 #include <compat/freebsd32/freebsd32_proto.h>
63 extern struct sysentvec ia32_freebsd_sysvec;
66 extern struct sysentvec elf32_freebsd_sysvec;
67 extern struct sysentvec elf64_freebsd_sysvec;
69 static d_close_t filemon_close;
70 static d_ioctl_t filemon_ioctl;
71 static d_open_t filemon_open;
72 static int filemon_unload(void);
73 static void filemon_load(void *);
75 static struct cdevsw filemon_cdevsw = {
76 .d_version = D_VERSION,
77 .d_close = filemon_close,
78 .d_ioctl = filemon_ioctl,
79 .d_open = filemon_open,
83 MALLOC_DECLARE(M_FILEMON);
84 MALLOC_DEFINE(M_FILEMON, "filemon", "File access monitor");
87 TAILQ_ENTRY(filemon) link; /* Link into the in-use list. */
88 struct mtx mtx; /* Lock mutex for this filemon. */
89 struct cv cv; /* Lock condition variable for this
91 struct file *fp; /* Output file pointer. */
92 struct thread *locker; /* Ptr to the thread locking this
94 pid_t pid; /* The process ID being monitored. */
95 char fname1[MAXPATHLEN]; /* Temporary filename buffer. */
96 char fname2[MAXPATHLEN]; /* Temporary filename buffer. */
97 char msgbufr[1024]; /* Output message buffer. */
100 static TAILQ_HEAD(, filemon) filemons_inuse = TAILQ_HEAD_INITIALIZER(filemons_inuse);
101 static TAILQ_HEAD(, filemon) filemons_free = TAILQ_HEAD_INITIALIZER(filemons_free);
102 static int n_readers = 0;
103 static struct mtx access_mtx;
104 static struct cv access_cv;
105 static struct thread *access_owner = NULL;
106 static struct thread *access_requester = NULL;
108 static struct cdev *filemon_dev;
110 #include "filemon_lock.c"
111 #include "filemon_wrapper.c"
114 filemon_dtr(void *data)
116 struct filemon *filemon = data;
118 if (filemon != NULL) {
119 struct file *fp = filemon->fp;
121 /* Get exclusive write access. */
122 filemon_lock_write();
124 /* Remove from the in-use list. */
125 TAILQ_REMOVE(&filemons_inuse, filemon, link);
130 /* Add to the free list. */
131 TAILQ_INSERT_TAIL(&filemons_free, filemon, link);
133 /* Give up write access. */
134 filemon_unlock_write();
137 fdrop(fp, curthread);
142 filemon_ioctl(struct cdev *dev, u_long cmd, caddr_t data, int flag __unused,
146 struct filemon *filemon;
148 #if __FreeBSD_version >= 900041
152 devfs_get_cdevpriv((void **) &filemon);
155 /* Set the output file descriptor. */
157 error = fget_write(td, *(int *)data,
158 #if __FreeBSD_version >= 900041
159 cap_rights_init(&rights, CAP_PWRITE),
163 /* Write the file header. */
164 filemon_comment(filemon);
167 /* Set the monitored process ID. */
168 case FILEMON_SET_PID:
169 error = pget(*((pid_t *)data), PGET_CANDEBUG | PGET_NOTWEXIT,
172 filemon->pid = p->p_pid;
186 filemon_open(struct cdev *dev, int oflags __unused, int devtype __unused,
187 struct thread *td __unused)
189 struct filemon *filemon;
191 /* Get exclusive write access. */
192 filemon_lock_write();
194 if ((filemon = TAILQ_FIRST(&filemons_free)) != NULL)
195 TAILQ_REMOVE(&filemons_free, filemon, link);
197 /* Give up write access. */
198 filemon_unlock_write();
200 if (filemon == NULL) {
201 filemon = malloc(sizeof(struct filemon), M_FILEMON,
206 mtx_init(&filemon->mtx, "filemon", "filemon", MTX_DEF);
207 cv_init(&filemon->cv, "filemon");
210 filemon->pid = curproc->p_pid;
212 devfs_set_cdevpriv(filemon, filemon_dtr);
214 /* Get exclusive write access. */
215 filemon_lock_write();
217 /* Add to the in-use list. */
218 TAILQ_INSERT_TAIL(&filemons_inuse, filemon, link);
220 /* Give up write access. */
221 filemon_unlock_write();
227 filemon_close(struct cdev *dev __unused, int flag __unused, int fmt __unused,
228 struct thread *td __unused)
235 filemon_load(void *dummy __unused)
237 mtx_init(&access_mtx, "filemon", "filemon", MTX_DEF);
238 cv_init(&access_cv, "filemon");
240 /* Install the syscall wrappers. */
241 filemon_wrapper_install();
243 filemon_dev = make_dev(&filemon_cdevsw, 0, UID_ROOT, GID_WHEEL, 0666,
250 struct filemon *filemon;
253 /* Get exclusive write access. */
254 filemon_lock_write();
256 if (TAILQ_FIRST(&filemons_inuse) != NULL)
259 destroy_dev(filemon_dev);
261 /* Deinstall the syscall wrappers. */
262 filemon_wrapper_deinstall();
265 /* Give up write access. */
266 filemon_unlock_write();
269 /* free() filemon structs free list. */
270 filemon_lock_write();
271 while ((filemon = TAILQ_FIRST(&filemons_free)) != NULL) {
272 TAILQ_REMOVE(&filemons_free, filemon, link);
273 mtx_destroy(&filemon->mtx);
274 cv_destroy(&filemon->cv);
275 free(filemon, M_FILEMON);
277 filemon_unlock_write();
279 mtx_destroy(&access_mtx);
280 cv_destroy(&access_cv);
287 filemon_modevent(module_t mod __unused, int type, void *data)
297 error = filemon_unload();
312 DEV_MODULE(filemon, filemon_modevent, NULL);
313 MODULE_VERSION(filemon, 1);