X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=security%2Fselinux%2Fss%2Fmls.c;h=7bc5b6440f70ba1ab45a66d0a7b3152d394096af;hb=43bc926fffd92024b46cafaf7350d669ba9ca884;hp=756036bcc243190858f997a0eb1af79942f3869d;hpb=cee37fe97739d85991964371c1f3a745c00dd236;p=linux-2.6.git

diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c
index 756036bcc..7bc5b6440 100644
--- a/security/selinux/ss/mls.c
+++ b/security/selinux/ss/mls.c
@@ -8,13 +8,14 @@
  *
  *	Support for enhanced MLS infrastructure.
  *
- * Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
+ * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  */
 
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/errno.h>
+#include "sidtab.h"
 #include "mls.h"
 #include "policydb.h"
 #include "services.h"
@@ -26,6 +27,7 @@
 int mls_compute_context_len(struct context * context)
 {
 	int i, l, len, range;
+	struct ebitmap_node *node;
 
 	if (!selinux_mls_enabled)
 		return 0;
@@ -35,24 +37,24 @@ int mls_compute_context_len(struct context * context)
 		range = 0;
 		len += strlen(policydb.p_sens_val_to_name[context->range.level[l].sens - 1]);
 
-		for (i = 1; i <= ebitmap_length(&context->range.level[l].cat); i++) {
-			if (ebitmap_get_bit(&context->range.level[l].cat, i - 1)) {
+		ebitmap_for_each_bit(&context->range.level[l].cat, node, i) {
+			if (ebitmap_node_get_bit(node, i)) {
 				if (range) {
 					range++;
 					continue;
 				}
 
-				len += strlen(policydb.p_cat_val_to_name[i - 1]) + 1;
+				len += strlen(policydb.p_cat_val_to_name[i]) + 1;
 				range++;
 			} else {
 				if (range > 1)
-					len += strlen(policydb.p_cat_val_to_name[i - 2]) + 1;
+					len += strlen(policydb.p_cat_val_to_name[i - 1]) + 1;
 				range = 0;
 			}
 		}
 		/* Handle case where last category is the end of range */
 		if (range > 1)
-			len += strlen(policydb.p_cat_val_to_name[i - 2]) + 1;
+			len += strlen(policydb.p_cat_val_to_name[i - 1]) + 1;
 
 		if (l == 0) {
 			if (mls_level_eq(&context->range.level[0],
@@ -76,6 +78,7 @@ void mls_sid_to_context(struct context *context,
 {
 	char *scontextp;
 	int i, l, range, wrote_sep;
+	struct ebitmap_node *node;
 
 	if (!selinux_mls_enabled)
 		return;
@@ -93,8 +96,8 @@ void mls_sid_to_context(struct context *context,
 		scontextp += strlen(policydb.p_sens_val_to_name[context->range.level[l].sens - 1]);
 
 		/* categories */
-		for (i = 1; i <= ebitmap_length(&context->range.level[l].cat); i++) {
-			if (ebitmap_get_bit(&context->range.level[l].cat, i - 1)) {
+		ebitmap_for_each_bit(&context->range.level[l].cat, node, i) {
+			if (ebitmap_node_get_bit(node, i)) {
 				if (range) {
 					range++;
 					continue;
@@ -105,8 +108,8 @@ void mls_sid_to_context(struct context *context,
 					wrote_sep = 1;
 				} else
 					*scontextp++ = ',';
-				strcpy(scontextp, policydb.p_cat_val_to_name[i - 1]);
-				scontextp += strlen(policydb.p_cat_val_to_name[i - 1]);
+				strcpy(scontextp, policydb.p_cat_val_to_name[i]);
+				scontextp += strlen(policydb.p_cat_val_to_name[i]);
 				range++;
 			} else {
 				if (range > 1) {
@@ -115,8 +118,8 @@ void mls_sid_to_context(struct context *context,
 					else
 						*scontextp++ = ',';
 
-					strcpy(scontextp, policydb.p_cat_val_to_name[i - 2]);
-					scontextp += strlen(policydb.p_cat_val_to_name[i - 2]);
+					strcpy(scontextp, policydb.p_cat_val_to_name[i - 1]);
+					scontextp += strlen(policydb.p_cat_val_to_name[i - 1]);
 				}
 				range = 0;
 			}
@@ -129,8 +132,8 @@ void mls_sid_to_context(struct context *context,
 			else
 				*scontextp++ = ',';
 
-			strcpy(scontextp, policydb.p_cat_val_to_name[i - 2]);
-			scontextp += strlen(policydb.p_cat_val_to_name[i - 2]);
+			strcpy(scontextp, policydb.p_cat_val_to_name[i - 1]);
+			scontextp += strlen(policydb.p_cat_val_to_name[i - 1]);
 		}
 
 		if (l == 0) {
@@ -156,6 +159,7 @@ int mls_context_isvalid(struct policydb *p, struct context *c)
 {
 	struct level_datum *levdatum;
 	struct user_datum *usrdatum;
+	struct ebitmap_node *node;
 	int i, l;
 
 	if (!selinux_mls_enabled)
@@ -178,11 +182,11 @@ int mls_context_isvalid(struct policydb *p, struct context *c)
 		if (!levdatum)
 			return 0;
 
-		for (i = 1; i <= ebitmap_length(&c->range.level[l].cat); i++) {
-			if (ebitmap_get_bit(&c->range.level[l].cat, i - 1)) {
+		ebitmap_for_each_bit(&c->range.level[l].cat, node, i) {
+			if (ebitmap_node_get_bit(node, i)) {
 				if (i > p->p_cats.nprim)
 					return 0;
-				if (!ebitmap_get_bit(&levdatum->level->cat, i - 1))
+				if (!ebitmap_get_bit(&levdatum->level->cat, i))
 					/*
 					 * Category may not be associated with
 					 * sensitivity in low level.
@@ -207,6 +211,26 @@ int mls_context_isvalid(struct policydb *p, struct context *c)
 	return 1;
 }
 
+/*
+ * Copies the MLS range from `src' into `dst'.
+ */
+static inline int mls_copy_context(struct context *dst,
+				   struct context *src)
+{
+	int l, rc = 0;
+
+	/* Copy the MLS range from the source context */
+	for (l = 0; l < 2; l++) {
+		dst->range.level[l].sens = src->range.level[l].sens;
+		rc = ebitmap_cpy(&dst->range.level[l].cat,
+				 &src->range.level[l].cat);
+		if (rc)
+			break;
+	}
+
+	return rc;
+}
+
 /*
  * Set the MLS fields in the security context structure
  * `context' based on the string representation in
@@ -216,10 +240,20 @@ int mls_context_isvalid(struct policydb *p, struct context *c)
  *
  * This function modifies the string in place, inserting
  * NULL characters to terminate the MLS fields.
+ *
+ * If a def_sid is provided and no MLS field is present,
+ * copy the MLS field of the associated default context.
+ * Used for upgraded to MLS systems where objects may lack
+ * MLS fields.
+ *
+ * Policy read-lock must be held for sidtab lookup.
+ *
  */
 int mls_context_to_sid(char oldc,
 		       char **scontext,
-		       struct context *context)
+		       struct context *context,
+		       struct sidtab *s,
+		       u32 def_sid)
 {
 
 	char delim;
@@ -228,12 +262,29 @@ int mls_context_to_sid(char oldc,
 	struct cat_datum *catdatum, *rngdatum;
 	int l, rc = -EINVAL;
 
-	if (!selinux_mls_enabled)
+	if (!selinux_mls_enabled) {
+		if (def_sid != SECSID_NULL && oldc)
+			*scontext += strlen(*scontext)+1;
 		return 0;
+	}
 
-	/* No MLS component to the security context. */
-	if (!oldc)
+	/*
+	 * No MLS component to the security context, try and map to
+	 * default if provided.
+	 */
+	if (!oldc) {
+		struct context *defcon;
+
+		if (def_sid == SECSID_NULL)
+			goto out;
+
+		defcon = sidtab_search(s, def_sid);
+		if (!defcon)
+			goto out;
+
+		rc = mls_copy_context(context, defcon);
 		goto out;
+	}
 
 	/* Extract low sensitivity. */
 	scontextp = p = *scontext;
@@ -334,20 +385,28 @@ out:
 }
 
 /*
- * Copies the MLS range from `src' into `dst'.
+ * Set the MLS fields in the security context structure
+ * `context' based on the string representation in
+ * the string `str'.  This function will allocate temporary memory with the
+ * given constraints of gfp_mask.
  */
-static inline int mls_copy_context(struct context *dst,
-				   struct context *src)
+int mls_from_string(char *str, struct context *context, gfp_t gfp_mask)
 {
-	int l, rc = 0;
+	char *tmpstr, *freestr;
+	int rc;
 
-	/* Copy the MLS range from the source context */
-	for (l = 0; l < 2; l++) {
-		dst->range.level[l].sens = src->range.level[l].sens;
-		rc = ebitmap_cpy(&dst->range.level[l].cat,
-				 &src->range.level[l].cat);
-		if (rc)
-			break;
+	if (!selinux_mls_enabled)
+		return -EINVAL;
+
+	/* we need freestr because mls_context_to_sid will change
+	   the value of tmpstr */
+	tmpstr = freestr = kstrdup(str, gfp_mask);
+	if (!tmpstr) {
+		rc = -ENOMEM;
+	} else {
+		rc = mls_context_to_sid(':', &tmpstr, context,
+		                        NULL, SECSID_NULL);
+		kfree(freestr);
 	}
 
 	return rc;
@@ -443,6 +502,7 @@ int mls_convert_context(struct policydb *oldp,
 	struct level_datum *levdatum;
 	struct cat_datum *catdatum;
 	struct ebitmap bitmap;
+	struct ebitmap_node *node;
 	int l, i;
 
 	if (!selinux_mls_enabled)
@@ -457,12 +517,12 @@ int mls_convert_context(struct policydb *oldp,
 		c->range.level[l].sens = levdatum->level->sens;
 
 		ebitmap_init(&bitmap);
-		for (i = 1; i <= ebitmap_length(&c->range.level[l].cat); i++) {
-			if (ebitmap_get_bit(&c->range.level[l].cat, i - 1)) {
+		ebitmap_for_each_bit(&c->range.level[l].cat, node, i) {
+			if (ebitmap_node_get_bit(node, i)) {
 				int rc;
 
 				catdatum = hashtab_search(newp->p_cats.table,
-				         	oldp->p_cat_val_to_name[i - 1]);
+				         	oldp->p_cat_val_to_name[i]);
 				if (!catdatum)
 					return -EINVAL;
 				rc = ebitmap_set_bit(&bitmap, catdatum->value - 1, 1);