ima: store the builtin/custom template definitions in a list

The builtin and single custom templates are currently stored in an
array.  In preparation for being able to restore a measurement list
containing multiple builtin/custom templates, this patch stores the
builtin and custom templates as a linked list.  This will permit
defining more than one custom template per boot.

Link: http://lkml.kernel.org/r/1480554346-29071-8-git-send-email-zohar@linux.vnet.ibm.com
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Andreas Steffen <andreas.steffen@strongswan.org>
Cc: Josh Sklar <sklar@linux.vnet.ibm.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stewart Smith <stewart@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Mimi Zohar 2016-12-19 16:22:51 -08:00 committed by Linus Torvalds
parent 7b8589cc29
commit 3f23d624de
3 changed files with 43 additions and 11 deletions

View File

@ -85,6 +85,7 @@ struct ima_template_field {
/* IMA template descriptor definition */
struct ima_template_desc {
struct list_head list;
char *name;
char *fmt;
int num_fields;
@ -146,6 +147,7 @@ int ima_restore_measurement_list(loff_t bufsize, void *buf);
int ima_measurements_show(struct seq_file *m, void *v);
unsigned long ima_get_binary_runtime_size(void);
int ima_init_template(void);
void ima_init_template_list(void);
/*
* used to protect h_table and sha_table

View File

@ -418,6 +418,7 @@ static int __init init_ima(void)
{
int error;
ima_init_template_list();
hash_setup(CONFIG_IMA_DEFAULT_HASH);
error = ima_init();
if (!error) {

View File

@ -15,16 +15,20 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/rculist.h>
#include "ima.h"
#include "ima_template_lib.h"
static struct ima_template_desc defined_templates[] = {
static struct ima_template_desc builtin_templates[] = {
{.name = IMA_TEMPLATE_IMA_NAME, .fmt = IMA_TEMPLATE_IMA_FMT},
{.name = "ima-ng", .fmt = "d-ng|n-ng"},
{.name = "ima-sig", .fmt = "d-ng|n-ng|sig"},
{.name = "", .fmt = ""}, /* placeholder for a custom format */
};
static LIST_HEAD(defined_templates);
static DEFINE_SPINLOCK(template_list);
static struct ima_template_field supported_fields[] = {
{.field_id = "d", .field_init = ima_eventdigest_init,
.field_show = ima_show_template_digest},
@ -53,6 +57,8 @@ static int __init ima_template_setup(char *str)
if (ima_template)
return 1;
ima_init_template_list();
/*
* Verify that a template with the supplied name exists.
* If not, use CONFIG_IMA_DEFAULT_TEMPLATE.
@ -81,7 +87,7 @@ __setup("ima_template=", ima_template_setup);
static int __init ima_template_fmt_setup(char *str)
{
int num_templates = ARRAY_SIZE(defined_templates);
int num_templates = ARRAY_SIZE(builtin_templates);
if (ima_template)
return 1;
@ -92,22 +98,28 @@ static int __init ima_template_fmt_setup(char *str)
return 1;
}
defined_templates[num_templates - 1].fmt = str;
ima_template = defined_templates + num_templates - 1;
builtin_templates[num_templates - 1].fmt = str;
ima_template = builtin_templates + num_templates - 1;
return 1;
}
__setup("ima_template_fmt=", ima_template_fmt_setup);
static struct ima_template_desc *lookup_template_desc(const char *name)
{
int i;
struct ima_template_desc *template_desc;
int found = 0;
for (i = 0; i < ARRAY_SIZE(defined_templates); i++) {
if (strcmp(defined_templates[i].name, name) == 0)
return defined_templates + i;
rcu_read_lock();
list_for_each_entry_rcu(template_desc, &defined_templates, list) {
if ((strcmp(template_desc->name, name) == 0) ||
(strcmp(template_desc->fmt, name) == 0)) {
found = 1;
break;
}
}
return NULL;
rcu_read_unlock();
return found ? template_desc : NULL;
}
static struct ima_template_field *lookup_template_field(const char *field_id)
@ -183,11 +195,28 @@ static int template_desc_init_fields(const char *template_fmt,
return 0;
}
void ima_init_template_list(void)
{
int i;
if (!list_empty(&defined_templates))
return;
spin_lock(&template_list);
for (i = 0; i < ARRAY_SIZE(builtin_templates); i++) {
list_add_tail_rcu(&builtin_templates[i].list,
&defined_templates);
}
spin_unlock(&template_list);
}
struct ima_template_desc *ima_template_desc_current(void)
{
if (!ima_template)
if (!ima_template) {
ima_init_template_list();
ima_template =
lookup_template_desc(CONFIG_IMA_DEFAULT_TEMPLATE);
}
return ima_template;
}