smack: convert smack to standard linux lists
the following patch (on top of 2.6.29) converts Smack lists to standard linux lists
Please review and consider for inclusion in 2.6.30-rc
regards,
Etienne
Signed-off-by: Etienne Basset <etienne.basset@numericable.fr>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c
index cfa19ca..5856419 100644
--- a/security/smack/smack_access.c
+++ b/security/smack/smack_access.c
@@ -16,48 +16,42 @@
#include "smack.h"
struct smack_known smack_known_huh = {
- .smk_next = NULL,
.smk_known = "?",
.smk_secid = 2,
.smk_cipso = NULL,
};
struct smack_known smack_known_hat = {
- .smk_next = &smack_known_huh,
.smk_known = "^",
.smk_secid = 3,
.smk_cipso = NULL,
};
struct smack_known smack_known_star = {
- .smk_next = &smack_known_hat,
.smk_known = "*",
.smk_secid = 4,
.smk_cipso = NULL,
};
struct smack_known smack_known_floor = {
- .smk_next = &smack_known_star,
.smk_known = "_",
.smk_secid = 5,
.smk_cipso = NULL,
};
struct smack_known smack_known_invalid = {
- .smk_next = &smack_known_floor,
.smk_known = "",
.smk_secid = 6,
.smk_cipso = NULL,
};
struct smack_known smack_known_web = {
- .smk_next = &smack_known_invalid,
.smk_known = "@",
.smk_secid = 7,
.smk_cipso = NULL,
};
-struct smack_known *smack_known = &smack_known_web;
+LIST_HEAD(smack_known_list);
/*
* The initial value needs to be bigger than any of the
@@ -87,7 +81,6 @@
int smk_access(char *subject_label, char *object_label, int request)
{
u32 may = MAY_NOT;
- struct smk_list_entry *sp;
struct smack_rule *srp;
/*
@@ -139,9 +132,8 @@
* access (e.g. read is included in readwrite) it's
* good.
*/
- for (sp = smack_list; sp != NULL; sp = sp->smk_next) {
- srp = &sp->smk_rule;
-
+ rcu_read_lock();
+ list_for_each_entry_rcu(srp, &smack_rule_list, list) {
if (srp->smk_subject == subject_label ||
strcmp(srp->smk_subject, subject_label) == 0) {
if (srp->smk_object == object_label ||
@@ -151,6 +143,7 @@
}
}
}
+ rcu_read_unlock();
/*
* This is a bit map operation.
*/
@@ -228,14 +221,17 @@
mutex_lock(&smack_known_lock);
- for (skp = smack_known; skp != NULL; skp = skp->smk_next)
- if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0)
+ found = 0;
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
+ found = 1;
break;
+ }
+ }
- if (skp == NULL) {
+ if (found == 0) {
skp = kzalloc(sizeof(struct smack_known), GFP_KERNEL);
if (skp != NULL) {
- skp->smk_next = smack_known;
strncpy(skp->smk_known, smack, SMK_MAXLEN);
skp->smk_secid = smack_next_secid++;
skp->smk_cipso = NULL;
@@ -244,8 +240,7 @@
* Make sure that the entry is actually
* filled before putting it on the list.
*/
- smp_mb();
- smack_known = skp;
+ list_add_rcu(&skp->list, &smack_known_list);
}
}
@@ -283,14 +278,19 @@
{
struct smack_known *skp;
- for (skp = smack_known; skp != NULL; skp = skp->smk_next)
- if (skp->smk_secid == secid)
+ rcu_read_lock();
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (skp->smk_secid == secid) {
+ rcu_read_unlock();
return skp->smk_known;
+ }
+ }
/*
* If we got this far someone asked for the translation
* of a secid that is not on the list.
*/
+ rcu_read_unlock();
return smack_known_invalid.smk_known;
}
@@ -305,9 +305,14 @@
{
struct smack_known *skp;
- for (skp = smack_known; skp != NULL; skp = skp->smk_next)
- if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0)
+ rcu_read_lock();
+ list_for_each_entry_rcu(skp, &smack_known_list, list) {
+ if (strncmp(skp->smk_known, smack, SMK_MAXLEN) == 0) {
+ rcu_read_unlock();
return skp->smk_secid;
+ }
+ }
+ rcu_read_unlock();
return 0;
}
@@ -332,7 +337,8 @@
struct smack_known *kp;
char *final = NULL;
- for (kp = smack_known; final == NULL && kp != NULL; kp = kp->smk_next) {
+ rcu_read_lock();
+ list_for_each_entry(kp, &smack_known_list, list) {
if (kp->smk_cipso == NULL)
continue;
@@ -344,6 +350,7 @@
spin_unlock_bh(&kp->smk_cipsolock);
}
+ rcu_read_unlock();
if (final == NULL)
final = smack_known_huh.smk_known;
strncpy(result, final, SMK_MAXLEN);
@@ -360,13 +367,19 @@
int smack_to_cipso(const char *smack, struct smack_cipso *cp)
{
struct smack_known *kp;
+ int found = 0;
- for (kp = smack_known; kp != NULL; kp = kp->smk_next)
+ rcu_read_lock();
+ list_for_each_entry_rcu(kp, &smack_known_list, list) {
if (kp->smk_known == smack ||
- strcmp(kp->smk_known, smack) == 0)
+ strcmp(kp->smk_known, smack) == 0) {
+ found = 1;
break;
+ }
+ }
+ rcu_read_unlock();
- if (kp == NULL || kp->smk_cipso == NULL)
+ if (found == 0 || kp->smk_cipso == NULL)
return -ENOENT;
memcpy(cp, kp->smk_cipso, sizeof(struct smack_cipso));