NetLabel: make netlbl_lsm_secattr struct easier/quicker to understand
The existing netlbl_lsm_secattr struct required the LSM to check all of the
fields to determine if any security attributes were present resulting in a lot
of work in the common case of no attributes. This patch adds a 'flags' field
which is used to indicate which attributes are present in the structure; this
should allow the LSM to do a quick comparison to determine if the structure
holds any security attributes.
Example:
if (netlbl_lsm_secattr->flags)
/* security attributes present */
else
/* NO security attributes present */
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/include/net/netlabel.h b/include/net/netlabel.h
index 4e223aa..d605d79 100644
--- a/include/net/netlabel.h
+++ b/include/net/netlabel.h
@@ -111,11 +111,17 @@
void (*free) (const void *data);
void *data;
};
+#define NETLBL_SECATTR_NONE 0x00000000
+#define NETLBL_SECATTR_DOMAIN 0x00000001
+#define NETLBL_SECATTR_CACHE 0x00000002
+#define NETLBL_SECATTR_MLS_LVL 0x00000004
+#define NETLBL_SECATTR_MLS_CAT 0x00000008
struct netlbl_lsm_secattr {
+ u32 flags;
+
char *domain;
u32 mls_lvl;
- u32 mls_lvl_vld;
unsigned char *mls_cat;
size_t mls_cat_len;
@@ -174,7 +180,10 @@
*/
static inline void netlbl_secattr_init(struct netlbl_lsm_secattr *secattr)
{
- memset(secattr, 0, sizeof(*secattr));
+ secattr->flags = 0;
+ secattr->domain = NULL;
+ secattr->mls_cat = NULL;
+ secattr->cache = NULL;
}
/**
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 095038a..f0a0785 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -319,6 +319,7 @@
entry->activity += 1;
atomic_inc(&entry->lsm_data->refcount);
secattr->cache = entry->lsm_data;
+ secattr->flags |= NETLBL_SECATTR_CACHE;
if (prev_entry == NULL) {
spin_unlock_bh(&cipso_v4_cache[bkt].lock);
return 0;
@@ -991,12 +992,15 @@
unsigned char **buffer,
u32 *buffer_len)
{
- int ret_val = -EPERM;
+ int ret_val;
unsigned char *buf = NULL;
u32 buf_len;
u32 level;
- if (secattr->mls_cat) {
+ if ((secattr->flags & NETLBL_SECATTR_MLS_LVL) == 0)
+ return -EPERM;
+
+ if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
buf = kzalloc(CIPSO_V4_HDR_LEN + 4 + CIPSO_V4_TAG1_CAT_LEN,
GFP_ATOMIC);
if (buf == NULL)
@@ -1013,10 +1017,10 @@
/* This will send packets using the "optimized" format when
* possibile as specified in section 3.4.2.6 of the
* CIPSO draft. */
- if (cipso_v4_rbm_optfmt && (ret_val > 0 && ret_val < 10))
- ret_val = 10;
-
- buf_len = 4 + ret_val;
+ if (cipso_v4_rbm_optfmt && ret_val > 0 && ret_val <= 10)
+ buf_len = 14;
+ else
+ buf_len = 4 + ret_val;
} else {
buf = kzalloc(CIPSO_V4_HDR_LEN + 4, GFP_ATOMIC);
if (buf == NULL)
@@ -1070,7 +1074,7 @@
if (ret_val != 0)
return ret_val;
secattr->mls_lvl = level;
- secattr->mls_lvl_vld = 1;
+ secattr->flags |= NETLBL_SECATTR_MLS_LVL;
if (tag_len > 4) {
switch (doi_def->type) {
@@ -1094,8 +1098,10 @@
if (ret_val < 0) {
kfree(secattr->mls_cat);
return ret_val;
+ } else if (ret_val > 0) {
+ secattr->mls_cat_len = ret_val;
+ secattr->flags |= NETLBL_SECATTR_MLS_CAT;
}
- secattr->mls_cat_len = ret_val;
}
return 0;
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index ff97110..da2f197 100644
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -62,6 +62,9 @@
int ret_val = -ENOENT;
struct netlbl_dom_map *dom_entry;
+ if ((secattr->flags & NETLBL_SECATTR_DOMAIN) == 0)
+ return -ENOENT;
+
rcu_read_lock();
dom_entry = netlbl_domhsh_getentry(secattr->domain);
if (dom_entry == NULL)
@@ -200,7 +203,7 @@
int netlbl_cache_add(const struct sk_buff *skb,
const struct netlbl_lsm_secattr *secattr)
{
- if (secattr->cache == NULL)
+ if ((secattr->flags & NETLBL_SECATTR_CACHE) == 0)
return -ENOMSG;
if (CIPSO_V4_OPTEXIST(skb))
diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c
index 4088204..1f5bbb2 100644
--- a/security/selinux/ss/services.c
+++ b/security/selinux/ss/services.c
@@ -2254,8 +2254,6 @@
cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
if (cache == NULL)
goto netlbl_cache_add_return;
- secattr.cache->free = selinux_netlbl_cache_free;
- secattr.cache->data = (void *)cache;
cache->type = NETLBL_CACHE_T_MLS;
if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
@@ -2268,6 +2266,10 @@
cache->data.mls_label.level[0].sens = ctx->range.level[0].sens;
cache->data.mls_label.level[1].sens = ctx->range.level[0].sens;
+ secattr.cache->free = selinux_netlbl_cache_free;
+ secattr.cache->data = (void *)cache;
+ secattr.flags = NETLBL_SECATTR_CACHE;
+
netlbl_cache_add(skb, &secattr);
netlbl_cache_add_return:
@@ -2313,7 +2315,7 @@
POLICY_RDLOCK;
- if (secattr->cache) {
+ if (secattr->flags & NETLBL_SECATTR_CACHE) {
cache = NETLBL_CACHE(secattr->cache->data);
switch (cache->type) {
case NETLBL_CACHE_T_SID:
@@ -2346,7 +2348,7 @@
default:
goto netlbl_secattr_to_sid_return;
}
- } else if (secattr->mls_lvl_vld) {
+ } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
ctx = sidtab_search(&sidtab, base_sid);
if (ctx == NULL)
goto netlbl_secattr_to_sid_return;
@@ -2355,7 +2357,7 @@
ctx_new.role = ctx->role;
ctx_new.type = ctx->type;
mls_import_lvl(&ctx_new, secattr->mls_lvl, secattr->mls_lvl);
- if (secattr->mls_cat) {
+ if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
if (mls_import_cat(&ctx_new,
secattr->mls_cat,
secattr->mls_cat_len,
@@ -2414,11 +2416,13 @@
netlbl_secattr_init(&secattr);
rc = netlbl_skbuff_getattr(skb, &secattr);
- if (rc == 0)
+ if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
rc = selinux_netlbl_secattr_to_sid(skb,
&secattr,
base_sid,
sid);
+ else
+ *sid = SECSID_NULL;
netlbl_secattr_destroy(&secattr);
return rc;
@@ -2455,7 +2459,6 @@
secattr.domain = kstrdup(policydb.p_type_val_to_name[ctx->type - 1],
GFP_ATOMIC);
mls_export_lvl(ctx, &secattr.mls_lvl, NULL);
- secattr.mls_lvl_vld = 1;
rc = mls_export_cat(ctx,
&secattr.mls_cat,
&secattr.mls_cat_len,
@@ -2464,6 +2467,10 @@
if (rc != 0)
goto netlbl_socket_setsid_return;
+ secattr.flags |= NETLBL_SECATTR_DOMAIN | NETLBL_SECATTR_MLS_LVL;
+ if (secattr.mls_cat)
+ secattr.flags |= NETLBL_SECATTR_MLS_CAT;
+
rc = netlbl_socket_setattr(sock, &secattr);
if (rc == 0)
sksec->nlbl_state = NLBL_LABELED;
@@ -2564,6 +2571,7 @@
netlbl_secattr_init(&secattr);
if (netlbl_sock_getattr(sk, &secattr) == 0 &&
+ secattr.flags != NETLBL_SECATTR_NONE &&
selinux_netlbl_secattr_to_sid(NULL,
&secattr,
SECINITSID_UNLABELED,
@@ -2756,7 +2764,7 @@
sksec->nlbl_state == NLBL_LABELED) {
netlbl_secattr_init(&secattr);
rc = netlbl_socket_getattr(sock, &secattr);
- if (rc == 0 && (secattr.cache || secattr.mls_lvl_vld))
+ if (rc == 0 && secattr.flags != NETLBL_SECATTR_NONE)
rc = -EACCES;
netlbl_secattr_destroy(&secattr);
}