[apparmor] [PATCH 4/4] AppArmor: export known rlimit names/value mappings in securityfs

[John Johansen]

On 12/31/2011 02:24 PM, Kees Cook wrote:
> Since the parser needs to know which rlimits are known to the kernel,
> export the list via a mask file in the "rlimit" subdirectory in the
> securityfs "features" directory.
>
> Signed-off-by: Kees Cook<kees at ubuntu.com>
Acked-by: John Johansen <john.johansen at canonical.com>

> ---
>   security/apparmor/Makefile           |   24 ++++++++++++++++++------
>   security/apparmor/apparmorfs.c       |    2 ++
>   security/apparmor/include/resource.h |    4 ++++
>   security/apparmor/resource.c         |    5 +++++
>   4 files changed, 29 insertions(+), 6 deletions(-)
>
> diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile
> index 2dafe50..86103ce 100644
> --- a/security/apparmor/Makefile
> +++ b/security/apparmor/Makefile
> @@ -28,25 +28,37 @@ cmd_make-caps = echo "static const char *capability_names[] = {">  $@ ;\
>   #    [RLIMIT_STACK] = "stack",
>   #
>   # and build a second integer table (with the second sed cmd), that maps
> -# RLIMIT defines to the order defined in asm-generic/resource.h  Thi is
> +# RLIMIT defines to the order defined in asm-generic/resource.h  This is
>   # required by policy load to map policy ordering of RLIMITs to internal
>   # ordering for architectures that redefine an RLIMIT.
>   # Transforms lines from
>   #    #define RLIMIT_STACK		3	/* max stack size */
>   # to
>   # RLIMIT_STACK,
> +#
> +# and build the securityfs entries for the mapping.
> +# Transforms lines from
> +#    #define RLIMIT_FSIZE        1   /* Maximum filesize */
> +#    #define RLIMIT_STACK		3	/* max stack size */
> +# to
> +# #define AA_FS_RLIMIT_MASK "fsize stack"
>   quiet_cmd_make-rlim = GEN     $@
> -cmd_make-rlim = echo "static const char *rlim_names[] = {">  $@ ;\
> +cmd_make-rlim = echo "static const char *rlim_names[RLIM_NLIMITS] = {">  $@ ;\
>   	sed $<  >>  $@ -r -n \
>   	    -e 's/^\# ?define[ \t]+(RLIMIT_([A-Z0-9_]+)).*/[\1] = "\L\2",/p';\
>   	echo "};">>  $@ ;\
> -	echo "static const int rlim_map[] = {">>  $@ ;\
> +	echo "static const int rlim_map[RLIM_NLIMITS] = {">>  $@ ;\
>   	sed -r -n "s/^\# ?define[ \t]+(RLIMIT_[A-Z0-9_]+).*/\1,/p" $<  >>  $@ ;\
> -	echo "};">>  $@
> +	echo "};">>  $@ ; \
> +	echo -n '\#define AA_FS_RLIMIT_MASK "'>>  $@ ;\
> +	sed -r -n 's/^\# ?define[ \t]+RLIMIT_([A-Z0-9_]+).*/\L\1/p' $<  | \
> +	    tr '\n' ' ' | sed -e 's/ $$/"\n/'>>  $@
>
>   $(obj)/capability.o : $(obj)/capability_names.h
>   $(obj)/resource.o : $(obj)/rlim_names.h
> -$(obj)/capability_names.h : $(srctree)/include/linux/capability.h
> +$(obj)/capability_names.h : $(srctree)/include/linux/capability.h \
> +			    $(src)/Makefile
>   	$(call cmd,make-caps)
> -$(obj)/rlim_names.h : $(srctree)/include/asm-generic/resource.h
> +$(obj)/rlim_names.h : $(srctree)/include/asm-generic/resource.h \
> +		      $(src)/Makefile
>   	$(call cmd,make-rlim)
> diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
> index 435bd37..a8da3ec 100644
> --- a/security/apparmor/apparmorfs.c
> +++ b/security/apparmor/apparmorfs.c
> @@ -25,6 +25,7 @@
>   #include "include/audit.h"
>   #include "include/context.h"
>   #include "include/policy.h"
> +#include "include/resource.h"
>
>   /**
>    * aa_simple_write_to_buffer - common routine for getting policy from user
> @@ -203,6 +204,7 @@ static struct aa_fs_entry aa_fs_entry_features[] = {
>   	AA_FS_DIR("file",			aa_fs_entry_file),
>   	AA_FS_FILE_BOOLEAN("namespaces",	1),
>   	AA_FS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
> +	AA_FS_DIR("rlimit",			aa_fs_entry_rlimit),
>   	{ }
>   };
>
> diff --git a/security/apparmor/include/resource.h b/security/apparmor/include/resource.h
> index 02baec7..d8c123e 100644
> --- a/security/apparmor/include/resource.h
> +++ b/security/apparmor/include/resource.h
> @@ -18,6 +18,8 @@
>   #include<linux/resource.h>
>   #include<linux/sched.h>
>
> +#include "include/apparmorfs.h"
> +
>   struct aa_profile;
>
>   /* struct aa_rlimit - rlimit settings for the profile
> @@ -32,6 +34,8 @@ struct aa_rlimit {
>   	struct rlimit limits[RLIM_NLIMITS];
>   };
>
> +extern struct aa_fs_entry aa_fs_entry_rlimit[];
> +
>   int aa_map_resource(int resource);
>   int aa_task_setrlimit(struct aa_profile *profile, struct task_struct *,
>   		      unsigned int resource, struct rlimit *new_rlim);
> diff --git a/security/apparmor/resource.c b/security/apparmor/resource.c
> index a4136c1..72c25a4 100644
> --- a/security/apparmor/resource.c
> +++ b/security/apparmor/resource.c
> @@ -23,6 +23,11 @@
>    */
>   #include "rlim_names.h"
>
> +struct aa_fs_entry aa_fs_entry_rlimit[] = {
> +	AA_FS_FILE_STRING("mask", AA_FS_RLIMIT_MASK),
> +	{ }
> +};
> +
>   /* audit callback for resource specific fields */
>   static void audit_cb(struct audit_buffer *ab, void *va)
>   {