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/*
* Copyright (c) 1999-2005 Apple Computer, 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 Computer, 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.
*
* $FreeBSD$
*/
#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/sem.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 mtx evclass_mtx;
static struct evclass_list evclass_hash[EVCLASSMAP_HASH_TABLE_SIZE];
/*
* 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;
mtx_lock(&evclass_mtx);
evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE];
class = AU_NULL;
LIST_FOREACH(evc, &evcl->head, entry) {
if (evc->event == event) {
class = evc->class;
goto out;
}
}
out:
mtx_unlock(&evclass_mtx);
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);
mtx_lock(&evclass_mtx);
evcl = &evclass_hash[event % EVCLASSMAP_HASH_TABLE_SIZE];
LIST_FOREACH(evc, &evcl->head, entry) {
if (evc->event == event) {
evc->class = class;
mtx_unlock(&evclass_mtx);
free(evc_new, M_AUDITEVCLASS);
return;
}
}
evc = evc_new;
evc->event = event;
evc->class = class;
LIST_INSERT_HEAD(&evcl->head, evc, entry);
mtx_unlock(&evclass_mtx);
}
void
au_evclassmap_init(void)
{
int i;
mtx_init(&evclass_mtx, "evclass_mtx", NULL, MTX_DEF);
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, AU_NULL);
}
}
/*
* 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
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
flags_and_error_to_openevent(int oflags, int error)
{
au_event_t aevent;
/*
* Need to check only those flags we care about.
*/
oflags = oflags & (O_RDONLY | O_CREAT | O_TRUNC | O_RDWR | O_WRONLY);
/*
* These checks determine what flags are on with the condition that
* ONLY that combination is on, and no other flags are on.
*/
switch (oflags) {
case O_RDONLY:
aevent = AUE_OPEN_R;
break;
case (O_RDONLY | O_CREAT):
aevent = AUE_OPEN_RC;
break;
case (O_RDONLY | O_CREAT | O_TRUNC):
aevent = AUE_OPEN_RTC;
break;
case (O_RDONLY | O_TRUNC):
aevent = AUE_OPEN_RT;
break;
case O_RDWR:
aevent = AUE_OPEN_RW;
break;
case (O_RDWR | O_CREAT):
aevent = AUE_OPEN_RWC;
break;
case (O_RDWR | O_CREAT | O_TRUNC):
aevent = AUE_OPEN_RWTC;
break;
case (O_RDWR | O_TRUNC):
aevent = AUE_OPEN_RWT;
break;
case O_WRONLY:
aevent = AUE_OPEN_W;
break;
case (O_WRONLY | O_CREAT):
aevent = AUE_OPEN_WC;
break;
case (O_WRONLY | O_CREAT | O_TRUNC):
aevent = AUE_OPEN_WTC;
break;
case (O_WRONLY | O_TRUNC):
aevent = AUE_OPEN_WT;
break;
default:
aevent = AUE_OPEN;
break;
}
#if 0
/*
* Convert chatty errors to better matching events.
* Failures to find a file are really just attribute
* events - so recast them as such.
*
* XXXAUDIT: Solaris defines that AUE_OPEN will never be returned, it
* is just a placeholder. However, in Darwin we return that in
* preference to other events. For now, comment this out as we don't
* have a BSM conversion routine for AUE_OPEN.
*/
switch (aevent) {
case AUE_OPEN_R:
case AUE_OPEN_RT:
case AUE_OPEN_RW:
case AUE_OPEN_RWT:
case AUE_OPEN_W:
case AUE_OPEN_WT:
if (error == ENOENT)
aevent = AUE_OPEN;
}
#endif
return (aevent);
}
/*
* Convert a MSGCTL command to a specific event.
*/
int
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.
*/
int
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.
*/
int
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 directoty,
* 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.
*
* XXXRW: Since we combine two paths here, ideally a buffer of size
* MAXPATHLEN * 2 would be passed in.
*/
void
canon_path(struct thread *td, char *path, char *cpath)
{
char *bufp;
char *retbuf, *freebuf;
struct vnode *vnp;
struct filedesc *fdp;
int cisr, error, vfslocked;
WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
"canon_path() at %s:%d", __FILE__, __LINE__);
fdp = td->td_proc->p_fd;
bufp = path;
cisr = 0;
FILEDESC_LOCK(fdp);
if (*(path) == '/') {
while (*(bufp) == '/')
bufp++; /* Skip leading '/'s. */
/*
* If no process root, or it is the same as the system root,
* audit the path as passed in with a single '/'.
*/
if ((fdp->fd_rdir == NULL) ||
(fdp->fd_rdir == rootvnode)) {
vnp = NULL;
bufp--; /* Restore one '/'. */
} else {
vnp = fdp->fd_rdir; /* Use process root. */
vref(vnp);
}
} else {
vnp = fdp->fd_cdir; /* Prepend the current dir. */
cisr = (fdp->fd_rdir == fdp->fd_cdir);
vref(vnp);
bufp = path;
}
FILEDESC_UNLOCK(fdp);
if (vnp != NULL) {
/*
* XXX: vn_fullpath() on FreeBSD is "less reliable" than
* vn_getpath() on Darwin, so this will need more attention
* in the future. Also, the question and string bounding
* here seems a bit questionable and will also require
* attention.
*/
vfslocked = VFS_LOCK_GIANT(vnp->v_mount);
vn_lock(vnp, LK_EXCLUSIVE | LK_RETRY, td);
error = vn_fullpath(td, vnp, &retbuf, &freebuf);
if (error == 0) {
/* Copy and free buffer allocated by vn_fullpath().
* If the current working directory was the same as
* the root directory, and the path was a relative
* pathname, do not separate the two components with
* the '/' character.
*/
snprintf(cpath, MAXPATHLEN, "%s%s%s", retbuf,
cisr ? "" : "/", bufp);
free(freebuf, M_TEMP);
} else
cpath[0] = '\0';
vput(vnp);
VFS_UNLOCK_GIANT(vfslocked);
} else {
strlcpy(cpath, bufp, MAXPATHLEN);
}
}
|