| Current Path : /sys/security/audit/ |
FreeBSD hs32.drive.ne.jp 9.1-RELEASE FreeBSD 9.1-RELEASE #1: Wed Jan 14 12:18:08 JST 2015 root@hs32.drive.ne.jp:/sys/amd64/compile/hs32 amd64 |
| Current File : //sys/security/audit/audit_bsm_klib.c |
/*
* Copyright (c) 1999-2009 Apple Inc.
* Copyright (c) 2005 Robert N. M. Watson
* 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. Neither the name of Apple Inc. ("Apple") 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 APPLE AND ITS 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 APPLE OR ITS 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 <sys/cdefs.h>
__FBSDID("$FreeBSD: release/9.1.0/sys/security/audit/audit_bsm_klib.c 212425 2010-09-10 16:42:16Z mdf $");
#include <sys/param.h>
#include <sys/fcntl.h>
#include <sys/filedesc.h>
#include <sys/libkern.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/rwlock.h>
#include <sys/sem.h>
#include <sys/sbuf.h>
#include <sys/syscall.h>
#include <sys/sysctl.h>
#include <sys/sysent.h>
#include <sys/vnode.h>
#include <bsm/audit.h>
#include <bsm/audit_kevents.h>
#include <security/audit/audit.h>
#include <security/audit/audit_private.h>
/*
* Hash table functions for the audit event number to event class mask
* mapping.
*/
#define EVCLASSMAP_HASH_TABLE_SIZE 251
struct evclass_elem {
au_event_t event;
au_class_t class;
LIST_ENTRY(evclass_elem) entry;
};
struct evclass_list {
LIST_HEAD(, evclass_elem) head;
};
static MALLOC_DEFINE(M_AUDITEVCLASS, "audit_evclass", "Audit event class");
static struct rwlock evclass_lock;
static struct evclass_list evclass_hash[EVCLASSMAP_HASH_TABLE_SIZE];
#define EVCLASS_LOCK_INIT() rw_init(&evclass_lock, "evclass_lock")
#define EVCLASS_RLOCK() rw_rlock(&evclass_lock)
#define EVCLASS_RUNLOCK() rw_runlock(&evclass_lock)
#define EVCLASS_WLOCK() rw_wlock(&evclass_lock)
#define EVCLASS_WUNLOCK() rw_wunlock(&evclass_lock)
struct aue_open_event {
int aoe_flags;
au_event_t aoe_event;
};
static const struct aue_open_event aue_open[] = {
{ O_RDONLY, AUE_OPEN_R },
{ (O_RDONLY | O_CREAT), AUE_OPEN_RC },
{ (O_RDONLY | O_CREAT | O_TRUNC), AUE_OPEN_RTC },
{ (O_RDONLY | O_TRUNC), AUE_OPEN_RT },
{ O_RDWR, AUE_OPEN_RW },
{ (O_RDWR | O_CREAT), AUE_OPEN_RWC },
{ (O_RDWR | O_CREAT | O_TRUNC), AUE_OPEN_RWTC },
{ (O_RDWR | O_TRUNC), AUE_OPEN_RWT },
{ O_WRONLY, AUE_OPEN_W },
{ (O_WRONLY | O_CREAT), AUE_OPEN_WC },
{ (O_WRONLY | O_CREAT | O_TRUNC), AUE_OPEN_WTC },
{ (O_WRONLY | O_TRUNC), AUE_OPEN_WT },
};
static const int aue_open_count = sizeof(aue_open) / sizeof(aue_open[0]);
static const struct aue_open_event aue_openat[] = {
{ O_RDONLY, AUE_OPENAT_R },
{ (O_RDONLY | O_CREAT), AUE_OPENAT_RC },
{ (O_RDONLY | O_CREAT | O_TRUNC), AUE_OPENAT_RTC },
{ (O_RDONLY | O_TRUNC), AUE_OPENAT_RT },
{ O_RDWR, AUE_OPENAT_RW },
{ (O_RDWR | O_CREAT), AUE_OPENAT_RWC },
{ (O_RDWR | O_CREAT | O_TRUNC), AUE_OPENAT_RWTC },
{ (O_RDWR | O_TRUNC), AUE_OPENAT_RWT },
{ O_WRONLY, AUE_OPENAT_W },
{ (O_WRONLY | O_CREAT), AUE_OPENAT_WC },
{ (O_WRONLY | O_CREAT | O_TRUNC), AUE_OPENAT_WTC },
{ (O_WRONLY | O_TRUNC), AUE_OPENAT_WT },
};
static const int aue_openat_count = sizeof(aue_openat) / sizeof(aue_openat[0]);
/*
* Look up the class for an audit event in the class mapping table.
*/
au_class_t
au_event_class(au_event_t event)
{
struct evclass_list *evcl;
struct evclass_elem *evc;
au_class_t class;
EVCLASS_RLOCK();
evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE];
class = 0;
LIST_FOREACH(evc, &evcl->head, entry) {
if (evc->event == event) {
class = evc->class;
goto out;
}
}
out:
EVCLASS_RUNLOCK();
return (class);
}
/*
* Insert a event to class mapping. If the event already exists in the
* mapping, then replace the mapping with the new one.
*
* XXX There is currently no constraints placed on the number of mappings.
* May want to either limit to a number, or in terms of memory usage.
*/
void
au_evclassmap_insert(au_event_t event, au_class_t class)
{
struct evclass_list *evcl;
struct evclass_elem *evc, *evc_new;
/*
* Pessimistically, always allocate storage before acquiring mutex.
* Free if there is already a mapping for this event.
*/
evc_new = malloc(sizeof(*evc), M_AUDITEVCLASS, M_WAITOK);
EVCLASS_WLOCK();
evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE];
LIST_FOREACH(evc, &evcl->head, entry) {
if (evc->event == event) {
evc->class = class;
EVCLASS_WUNLOCK();
free(evc_new, M_AUDITEVCLASS);
return;
}
}
evc = evc_new;
evc->event = event;
evc->class = class;
LIST_INSERT_HEAD(&evcl->head, evc, entry);
EVCLASS_WUNLOCK();
}
void
au_evclassmap_init(void)
{
int i;
EVCLASS_LOCK_INIT();
for (i = 0; i < EVCLASSMAP_HASH_TABLE_SIZE; i++)
LIST_INIT(&evclass_hash[i].head);
/*
* Set up the initial event to class mapping for system calls.
*
* XXXRW: Really, this should walk all possible audit events, not all
* native ABI system calls, as there may be audit events reachable
* only through non-native system calls. It also seems a shame to
* frob the mutex this early.
*/
for (i = 0; i < SYS_MAXSYSCALL; i++) {
if (sysent[i].sy_auevent != AUE_NULL)
au_evclassmap_insert(sysent[i].sy_auevent, 0);
}
}
/*
* Check whether an event is aditable by comparing the mask of classes this
* event is part of against the given mask.
*/
int
au_preselect(au_event_t event, au_class_t class, au_mask_t *mask_p, int sorf)
{
au_class_t effmask = 0;
if (mask_p == NULL)
return (-1);
/*
* Perform the actual check of the masks against the event.
*/
if (sorf & AU_PRS_SUCCESS)
effmask |= (mask_p->am_success & class);
if (sorf & AU_PRS_FAILURE)
effmask |= (mask_p->am_failure & class);
if (effmask)
return (1);
else
return (0);
}
/*
* Convert sysctl names and present arguments to events.
*/
au_event_t
audit_ctlname_to_sysctlevent(int name[], uint64_t valid_arg)
{
/* can't parse it - so return the worst case */
if ((valid_arg & (ARG_CTLNAME | ARG_LEN)) != (ARG_CTLNAME | ARG_LEN))
return (AUE_SYSCTL);
switch (name[0]) {
/* non-admin "lookups" treat them special */
case KERN_OSTYPE:
case KERN_OSRELEASE:
case KERN_OSREV:
case KERN_VERSION:
case KERN_ARGMAX:
case KERN_CLOCKRATE:
case KERN_BOOTTIME:
case KERN_POSIX1:
case KERN_NGROUPS:
case KERN_JOB_CONTROL:
case KERN_SAVED_IDS:
case KERN_OSRELDATE:
case KERN_DUMMY:
return (AUE_SYSCTL_NONADMIN);
/* only treat the changeable controls as admin */
case KERN_MAXVNODES:
case KERN_MAXPROC:
case KERN_MAXFILES:
case KERN_MAXPROCPERUID:
case KERN_MAXFILESPERPROC:
case KERN_HOSTID:
case KERN_SECURELVL:
case KERN_HOSTNAME:
case KERN_VNODE:
case KERN_PROC:
case KERN_FILE:
case KERN_PROF:
case KERN_NISDOMAINNAME:
case KERN_UPDATEINTERVAL:
case KERN_NTP_PLL:
case KERN_BOOTFILE:
case KERN_DUMPDEV:
case KERN_IPC:
case KERN_PS_STRINGS:
case KERN_USRSTACK:
case KERN_LOGSIGEXIT:
case KERN_IOV_MAX:
case KERN_MAXID:
return ((valid_arg & ARG_VALUE) ?
AUE_SYSCTL : AUE_SYSCTL_NONADMIN);
default:
return (AUE_SYSCTL);
}
/* NOTREACHED */
}
/*
* Convert an open flags specifier into a specific type of open event for
* auditing purposes.
*/
au_event_t
audit_flags_and_error_to_openevent(int oflags, int error)
{
int i;
/*
* Need to check only those flags we care about.
*/
oflags = oflags & (O_RDONLY | O_CREAT | O_TRUNC | O_RDWR | O_WRONLY);
for (i = 0; i < aue_open_count; i++) {
if (aue_open[i].aoe_flags == oflags)
return (aue_open[i].aoe_event);
}
return (AUE_OPEN);
}
au_event_t
audit_flags_and_error_to_openatevent(int oflags, int error)
{
int i;
/*
* Need to check only those flags we care about.
*/
oflags = oflags & (O_RDONLY | O_CREAT | O_TRUNC | O_RDWR | O_WRONLY);
for (i = 0; i < aue_openat_count; i++) {
if (aue_openat[i].aoe_flags == oflags)
return (aue_openat[i].aoe_event);
}
return (AUE_OPENAT);
}
/*
* Convert a MSGCTL command to a specific event.
*/
au_event_t
audit_msgctl_to_event(int cmd)
{
switch (cmd) {
case IPC_RMID:
return (AUE_MSGCTL_RMID);
case IPC_SET:
return (AUE_MSGCTL_SET);
case IPC_STAT:
return (AUE_MSGCTL_STAT);
default:
/* We will audit a bad command. */
return (AUE_MSGCTL);
}
}
/*
* Convert a SEMCTL command to a specific event.
*/
au_event_t
audit_semctl_to_event(int cmd)
{
switch (cmd) {
case GETALL:
return (AUE_SEMCTL_GETALL);
case GETNCNT:
return (AUE_SEMCTL_GETNCNT);
case GETPID:
return (AUE_SEMCTL_GETPID);
case GETVAL:
return (AUE_SEMCTL_GETVAL);
case GETZCNT:
return (AUE_SEMCTL_GETZCNT);
case IPC_RMID:
return (AUE_SEMCTL_RMID);
case IPC_SET:
return (AUE_SEMCTL_SET);
case SETALL:
return (AUE_SEMCTL_SETALL);
case SETVAL:
return (AUE_SEMCTL_SETVAL);
case IPC_STAT:
return (AUE_SEMCTL_STAT);
default:
/* We will audit a bad command. */
return (AUE_SEMCTL);
}
}
/*
* Convert a command for the auditon() system call to a audit event.
*/
au_event_t
auditon_command_event(int cmd)
{
switch(cmd) {
case A_GETPOLICY:
return (AUE_AUDITON_GPOLICY);
case A_SETPOLICY:
return (AUE_AUDITON_SPOLICY);
case A_GETKMASK:
return (AUE_AUDITON_GETKMASK);
case A_SETKMASK:
return (AUE_AUDITON_SETKMASK);
case A_GETQCTRL:
return (AUE_AUDITON_GQCTRL);
case A_SETQCTRL:
return (AUE_AUDITON_SQCTRL);
case A_GETCWD:
return (AUE_AUDITON_GETCWD);
case A_GETCAR:
return (AUE_AUDITON_GETCAR);
case A_GETSTAT:
return (AUE_AUDITON_GETSTAT);
case A_SETSTAT:
return (AUE_AUDITON_SETSTAT);
case A_SETUMASK:
return (AUE_AUDITON_SETUMASK);
case A_SETSMASK:
return (AUE_AUDITON_SETSMASK);
case A_GETCOND:
return (AUE_AUDITON_GETCOND);
case A_SETCOND:
return (AUE_AUDITON_SETCOND);
case A_GETCLASS:
return (AUE_AUDITON_GETCLASS);
case A_SETCLASS:
return (AUE_AUDITON_SETCLASS);
case A_GETPINFO:
case A_SETPMASK:
case A_SETFSIZE:
case A_GETFSIZE:
case A_GETPINFO_ADDR:
case A_GETKAUDIT:
case A_SETKAUDIT:
default:
return (AUE_AUDITON); /* No special record */
}
}
/*
* Create a canonical path from given path by prefixing either the root
* directory, or the current working directory. If the process working
* directory is NULL, we could use 'rootvnode' to obtain the root directory,
* but this results in a volfs name written to the audit log. So we will
* leave the filename starting with '/' in the audit log in this case.
*/
void
audit_canon_path(struct thread *td, char *path, char *cpath)
{
struct vnode *cvnp, *rvnp;
char *rbuf, *fbuf, *copy;
struct filedesc *fdp;
struct sbuf sbf;
int error, cwir;
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL, "%s: at %s:%d",
__func__, __FILE__, __LINE__);
copy = path;
rvnp = cvnp = NULL;
fdp = td->td_proc->p_fd;
FILEDESC_SLOCK(fdp);
/*
* Make sure that we handle the chroot(2) case. If there is an
* alternate root directory, prepend it to the audited pathname.
*/
if (fdp->fd_rdir != NULL && fdp->fd_rdir != rootvnode) {
rvnp = fdp->fd_rdir;
vhold(rvnp);
}
/*
* If the supplied path is relative, make sure we capture the current
* working directory so we can prepend it to the supplied relative
* path.
*/
if (*path != '/') {
cvnp = fdp->fd_cdir;
vhold(cvnp);
}
cwir = (fdp->fd_rdir == fdp->fd_cdir);
FILEDESC_SUNLOCK(fdp);
/*
* NB: We require that the supplied array be at least MAXPATHLEN bytes
* long. If this is not the case, then we can run into serious trouble.
*/
(void) sbuf_new(&sbf, cpath, MAXPATHLEN, SBUF_FIXEDLEN);
/*
* Strip leading forward slashes.
*/
while (*copy == '/')
copy++;
/*
* Make sure we handle chroot(2) and prepend the global path to these
* environments.
*
* NB: vn_fullpath(9) on FreeBSD is less reliable than vn_getpath(9)
* on Darwin. As a result, this may need some additional attention
* in the future.
*/
if (rvnp != NULL) {
error = vn_fullpath_global(td, rvnp, &rbuf, &fbuf);
vdrop(rvnp);
if (error) {
cpath[0] = '\0';
if (cvnp != NULL)
vdrop(cvnp);
return;
}
(void) sbuf_cat(&sbf, rbuf);
free(fbuf, M_TEMP);
}
if (cvnp != NULL) {
error = vn_fullpath(td, cvnp, &rbuf, &fbuf);
vdrop(cvnp);
if (error) {
cpath[0] = '\0';
return;
}
(void) sbuf_cat(&sbf, rbuf);
free(fbuf, M_TEMP);
}
if (cwir == 0 || (cwir != 0 && cvnp == NULL))
(void) sbuf_putc(&sbf, '/');
/*
* Now that we have processed any alternate root and relative path
* names, add the supplied pathname.
*/
(void) sbuf_cat(&sbf, copy);
/*
* One or more of the previous sbuf operations could have resulted in
* the supplied buffer being overflowed. Check to see if this is the
* case.
*/
if (sbuf_error(&sbf) != 0) {
cpath[0] = '\0';
return;
}
sbuf_finish(&sbf);
}