selinux: wrap global selinux state

Define a selinux state structure (struct selinux_state) for
global SELinux state and pass it explicitly to all security server
functions.  The public portion of the structure contains state
that is used throughout the SELinux code, such as the enforcing mode.
The structure also contains a pointer to a selinux_ss structure whose
definition is private to the security server and contains security
server specific state such as the policy database and SID table.

This change should have no effect on SELinux behavior or APIs
(userspace or LSM).  It merely wraps SELinux state and passes it
explicitly as needed.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
[PM: minor fixups needed due to collisions with the SCTP patches]
Signed-off-by: Paul Moore <paul@paul-moore.com>

1 files changed, 40 insertions, 32 deletions

diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index ad982ce8bfa4..39475fb455bc 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -33,20 +33,20 @@
  * Return the length in bytes for the MLS fields of the
  * security context string representation of `context'.
  */
-int mls_compute_context_len(struct context *context)
+int mls_compute_context_len(struct policydb *p, struct context *context)
 {
 	int i, l, len, head, prev;
 	char *nm;
 	struct ebitmap *e;
 	struct ebitmap_node *node;
 
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return 0;
 
 	len = 1; /* for the beginning ":" */
 	for (l = 0; l < 2; l++) {
 		int index_sens = context->range.level[l].sens;
-		len += strlen(sym_name(&policydb, SYM_LEVELS, index_sens - 1));
+		len += strlen(sym_name(p, SYM_LEVELS, index_sens - 1));
 
 		/* categories */
 		head = -2;
@@ -56,17 +56,17 @@ int mls_compute_context_len(struct context *context)
 			if (i - prev > 1) {
 				/* one or more negative bits are skipped */
 				if (head != prev) {
-					nm = sym_name(&policydb, SYM_CATS, prev);
+					nm = sym_name(p, SYM_CATS, prev);
 					len += strlen(nm) + 1;
 				}
-				nm = sym_name(&policydb, SYM_CATS, i);
+				nm = sym_name(p, SYM_CATS, i);
 				len += strlen(nm) + 1;
 				head = i;
 			}
 			prev = i;
 		}
 		if (prev != head) {
-			nm = sym_name(&policydb, SYM_CATS, prev);
+			nm = sym_name(p, SYM_CATS, prev);
 			len += strlen(nm) + 1;
 		}
 		if (l == 0) {
@@ -86,7 +86,8 @@ int mls_compute_context_len(struct context *context)
  * the MLS fields of `context' into the string `*scontext'.
  * Update `*scontext' to point to the end of the MLS fields.
  */
-void mls_sid_to_context(struct context *context,
+void mls_sid_to_context(struct policydb *p,
+			struct context *context,
 			char **scontext)
 {
 	char *scontextp, *nm;
@@ -94,7 +95,7 @@ void mls_sid_to_context(struct context *context,
 	struct ebitmap *e;
 	struct ebitmap_node *node;
 
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return;
 
 	scontextp = *scontext;
@@ -103,7 +104,7 @@ void mls_sid_to_context(struct context *context,
 	scontextp++;
 
 	for (l = 0; l < 2; l++) {
-		strcpy(scontextp, sym_name(&policydb, SYM_LEVELS,
+		strcpy(scontextp, sym_name(p, SYM_LEVELS,
 					   context->range.level[l].sens - 1));
 		scontextp += strlen(scontextp);
 
@@ -119,7 +120,7 @@ void mls_sid_to_context(struct context *context,
 						*scontextp++ = '.';
 					else
 						*scontextp++ = ',';
-					nm = sym_name(&policydb, SYM_CATS, prev);
+					nm = sym_name(p, SYM_CATS, prev);
 					strcpy(scontextp, nm);
 					scontextp += strlen(nm);
 				}
@@ -127,7 +128,7 @@ void mls_sid_to_context(struct context *context,
 					*scontextp++ = ':';
 				else
 					*scontextp++ = ',';
-				nm = sym_name(&policydb, SYM_CATS, i);
+				nm = sym_name(p, SYM_CATS, i);
 				strcpy(scontextp, nm);
 				scontextp += strlen(nm);
 				head = i;
@@ -140,7 +141,7 @@ void mls_sid_to_context(struct context *context,
 				*scontextp++ = '.';
 			else
 				*scontextp++ = ',';
-			nm = sym_name(&policydb, SYM_CATS, prev);
+			nm = sym_name(p, SYM_CATS, prev);
 			strcpy(scontextp, nm);
 			scontextp += strlen(nm);
 		}
@@ -375,12 +376,13 @@ out:
  * the string `str'.  This function will allocate temporary memory with the
  * given constraints of gfp_mask.
  */
-int mls_from_string(char *str, struct context *context, gfp_t gfp_mask)
+int mls_from_string(struct policydb *p, char *str, struct context *context,
+		    gfp_t gfp_mask)
 {
 	char *tmpstr, *freestr;
 	int rc;
 
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return -EINVAL;
 
 	/* we need freestr because mls_context_to_sid will change
@@ -389,7 +391,7 @@ int mls_from_string(char *str, struct context *context, gfp_t gfp_mask)
 	if (!tmpstr) {
 		rc = -ENOMEM;
 	} else {
-		rc = mls_context_to_sid(&policydb, ':', &tmpstr, context,
+		rc = mls_context_to_sid(p, ':', &tmpstr, context,
 					NULL, SECSID_NULL);
 		kfree(freestr);
 	}
@@ -417,10 +419,11 @@ int mls_range_set(struct context *context,
 	return rc;
 }
 
-int mls_setup_user_range(struct context *fromcon, struct user_datum *user,
+int mls_setup_user_range(struct policydb *p,
+			 struct context *fromcon, struct user_datum *user,
 			 struct context *usercon)
 {
-	if (policydb.mls_enabled) {
+	if (p->mls_enabled) {
 		struct mls_level *fromcon_sen = &(fromcon->range.level[0]);
 		struct mls_level *fromcon_clr = &(fromcon->range.level[1]);
 		struct mls_level *user_low = &(user->range.level[0]);
@@ -470,7 +473,7 @@ int mls_convert_context(struct policydb *oldp,
 	struct ebitmap_node *node;
 	int l, i;
 
-	if (!policydb.mls_enabled)
+	if (!oldp->mls_enabled || !newp->mls_enabled)
 		return 0;
 
 	for (l = 0; l < 2; l++) {
@@ -503,7 +506,8 @@ int mls_convert_context(struct policydb *oldp,
 	return 0;
 }
 
-int mls_compute_sid(struct context *scontext,
+int mls_compute_sid(struct policydb *p,
+		    struct context *scontext,
 		    struct context *tcontext,
 		    u16 tclass,
 		    u32 specified,
@@ -515,7 +519,7 @@ int mls_compute_sid(struct context *scontext,
 	struct class_datum *cladatum;
 	int default_range = 0;
 
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return 0;
 
 	switch (specified) {
@@ -524,12 +528,12 @@ int mls_compute_sid(struct context *scontext,
 		rtr.source_type = scontext->type;
 		rtr.target_type = tcontext->type;
 		rtr.target_class = tclass;
-		r = hashtab_search(policydb.range_tr, &rtr);
+		r = hashtab_search(p->range_tr, &rtr);
 		if (r)
 			return mls_range_set(newcontext, r);
 
-		if (tclass && tclass <= policydb.p_classes.nprim) {
-			cladatum = policydb.class_val_to_struct[tclass - 1];
+		if (tclass && tclass <= p->p_classes.nprim) {
+			cladatum = p->class_val_to_struct[tclass - 1];
 			if (cladatum)
 				default_range = cladatum->default_range;
 		}
@@ -551,7 +555,7 @@ int mls_compute_sid(struct context *scontext,
 
 		/* Fallthrough */
 	case AVTAB_CHANGE:
-		if ((tclass == policydb.process_class) || (sock == true))
+		if ((tclass == p->process_class) || (sock == true))
 			/* Use the process MLS attributes. */
 			return mls_context_cpy(newcontext, scontext);
 		else
@@ -577,10 +581,11 @@ int mls_compute_sid(struct context *scontext,
  * NetLabel MLS sensitivity level field.
  *
  */
-void mls_export_netlbl_lvl(struct context *context,
+void mls_export_netlbl_lvl(struct policydb *p,
+			   struct context *context,
 			   struct netlbl_lsm_secattr *secattr)
 {
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return;
 
 	secattr->attr.mls.lvl = context->range.level[0].sens - 1;
@@ -597,10 +602,11 @@ void mls_export_netlbl_lvl(struct context *context,
  * NetLabel MLS sensitivity level into the context.
  *
  */
-void mls_import_netlbl_lvl(struct context *context,
+void mls_import_netlbl_lvl(struct policydb *p,
+			   struct context *context,
 			   struct netlbl_lsm_secattr *secattr)
 {
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return;
 
 	context->range.level[0].sens = secattr->attr.mls.lvl + 1;
@@ -617,12 +623,13 @@ void mls_import_netlbl_lvl(struct context *context,
  * MLS category field.  Returns zero on success, negative values on failure.
  *
  */
-int mls_export_netlbl_cat(struct context *context,
+int mls_export_netlbl_cat(struct policydb *p,
+			  struct context *context,
 			  struct netlbl_lsm_secattr *secattr)
 {
 	int rc;
 
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return 0;
 
 	rc = ebitmap_netlbl_export(&context->range.level[0].cat,
@@ -645,12 +652,13 @@ int mls_export_netlbl_cat(struct context *context,
  * negative values on failure.
  *
  */
-int mls_import_netlbl_cat(struct context *context,
+int mls_import_netlbl_cat(struct policydb *p,
+			  struct context *context,
 			  struct netlbl_lsm_secattr *secattr)
 {
 	int rc;
 
-	if (!policydb.mls_enabled)
+	if (!p->mls_enabled)
 		return 0;
 
 	rc = ebitmap_netlbl_import(&context->range.level[0].cat,