On 2018-05-31 17:29, Steve Grubb wrote:
 On Thursday, May 31, 2018 4:23:09 PM EDT Richard Guy Briggs wrote:
 > The AUDIT_FILTER_TYPE name is vague and misleading due to not describing
 > where or when the filter is applied and obsolete due to its available
 > filter fields having been expanded.
 > 
 > Userspace has already renamed it from AUDIT_FILTER_TYPE to
 > AUDIT_FILTER_EXCLUDE without checking if it already exists.
 
 Historically speaking, this is not why it is the way it is. But I think it 
 doesn't mean that you cannot do something like this:
 
 #define AUDIT_FILTER_EXCLUDE    AUDIT_FILTER_TYPE 
I was originally hoping to do that, but that then causes a build error
on any previous version of audit userspace.
 It's easy then to add a #ifndef to the userspace code so that
there is an 
 easy migration. I also do not see any compiler warnings with the above in 
 both /usr/include/linux/audit.h and /usr/include/libaudit.h. 
I know it would be easy to fix and going forward userspace could adopt
the kernel one with
	#ifndef AUDIT_FILTER_EXCL
	#define AUDIT_FILTER_EXCL AUDIT_FILTER_TYPE
	#endif
I do have a minor preference for the shorter AUDIT_FILTER_EXCL.
The only place in userspace that AUDIT_FILTER_TYPE is used is grabbing
the value from the kernel to set AUDIT_FILTER_EXCLUDE, and in two bits
of documentation (since that is the published API for libaudit).
Might it make sense to still make AUDIT_FILTER_TYPE available for
libaudit users, but change over the documentation to use one of the
newer forms?
 -Steve
 
 > In order to
 > not cause userspace compile problems from duplicate definitions and to
 > more accurately and inclusively rename it in the kernel, while providing
 > a migration path for userspace, rename it to AUDIT_FILTER_EXCL.
 > 
 > See: 
https://github.com/linux-audit/audit-kernel/issues/89
 > 
 > Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com>
 > ---
 >  include/uapi/linux/audit.h |  3 ++-
 >  kernel/audit.c             |  2 +-
 >  kernel/auditfilter.c       | 10 +++++-----
 >  3 files changed, 8 insertions(+), 7 deletions(-)
 > 
 > diff --git a/include/uapi/linux/audit.h b/include/uapi/linux/audit.h
 > index 04f9bd2..45dd7ef 100644
 > --- a/include/uapi/linux/audit.h
 > +++ b/include/uapi/linux/audit.h
 > @@ -156,8 +156,9 @@
 >  #define AUDIT_FILTER_ENTRY	0x02	/* Apply rule at syscall entry */
 >  #define AUDIT_FILTER_WATCH	0x03	/* Apply rule to file system watches */
 >  #define AUDIT_FILTER_EXIT	0x04	/* Apply rule at syscall exit */
 > -#define AUDIT_FILTER_TYPE	0x05	/* Apply rule at audit_log_start */
 > +#define AUDIT_FILTER_EXCL	0x05	/* Apply rule at audit_log_start */
 >  #define AUDIT_FILTER_FS		0x06	/* Apply rule at __audit_inode_child */
 > +#define AUDIT_FILTER_TYPE	AUDIT_FILTER_EXCL /* obsolete misleading naming
 > */
 > 
 >  #define AUDIT_NR_FILTERS	7
 > 
 > diff --git a/kernel/audit.c b/kernel/audit.c
 > index 3a18e59..089cede 100644
 > --- a/kernel/audit.c
 > +++ b/kernel/audit.c
 > @@ -1754,7 +1754,7 @@ struct audit_buffer *audit_log_start(struct
 > audit_context *ctx, gfp_t gfp_mask, if (audit_initialized !=
 > AUDIT_INITIALIZED)
 >  		return NULL;
 > 
 > -	if (unlikely(!audit_filter(type, AUDIT_FILTER_TYPE)))
 > +	if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCL)))
 >  		return NULL;
 > 
 >  	/* NOTE: don't ever fail/sleep on these two conditions:
 > diff --git a/kernel/auditfilter.c b/kernel/auditfilter.c
 > index eaa3201..f17a42f5 100644
 > --- a/kernel/auditfilter.c
 > +++ b/kernel/auditfilter.c
 > @@ -264,7 +264,7 @@ static inline struct audit_entry
 > *audit_to_entry_common(struct audit_rule_data * case AUDIT_FILTER_TASK:
 >  #endif
 >  	case AUDIT_FILTER_USER:
 > -	case AUDIT_FILTER_TYPE:
 > +	case AUDIT_FILTER_EXCL:
 >  	case AUDIT_FILTER_FS:
 >  		;
 >  	}
 > @@ -337,7 +337,7 @@ static int audit_field_valid(struct audit_entry *entry,
 > struct audit_field *f) {
 >  	switch(f->type) {
 >  	case AUDIT_MSGTYPE:
 > -		if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
 > +		if (entry->rule.listnr != AUDIT_FILTER_EXCL &&
 >  		    entry->rule.listnr != AUDIT_FILTER_USER)
 >  			return -EINVAL;
 >  		break;
 > @@ -931,7 +931,7 @@ static inline int audit_add_rule(struct audit_entry
 > *entry) /* If any of these, don't count towards total */
 >  	switch(entry->rule.listnr) {
 >  	case AUDIT_FILTER_USER:
 > -	case AUDIT_FILTER_TYPE:
 > +	case AUDIT_FILTER_EXCL:
 >  	case AUDIT_FILTER_FS:
 >  		dont_count = 1;
 >  	}
 > @@ -1013,7 +1013,7 @@ int audit_del_rule(struct audit_entry *entry)
 >  	/* If any of these, don't count towards total */
 >  	switch(entry->rule.listnr) {
 >  	case AUDIT_FILTER_USER:
 > -	case AUDIT_FILTER_TYPE:
 > +	case AUDIT_FILTER_EXCL:
 >  	case AUDIT_FILTER_FS:
 >  		dont_count = 1;
 >  	}
 > @@ -1369,7 +1369,7 @@ int audit_filter(int msgtype, unsigned int listtype)
 >  				break;
 >  		}
 >  		if (result > 0) {
 > -			if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_TYPE)
 > +			if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCL)
 >  				ret = 0;
 >  			break;
 >  		}
 
 
 
  
- RGB
--
Richard Guy Briggs <rgb(a)redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635