SELinux: Remove security_get_policycaps()
[sfrench/cifs-2.6.git] / security / selinux / ss / services.c
index 6100fc023055c0b62e4d3d4691e0593424d38113..f374186012151e42ba197ac80391a147fb3821f7 100644 (file)
  * Updated: Hewlett-Packard <paul.moore@hp.com>
  *
  *      Added support for NetLabel
+ *      Added support for the policy capability bitmap
  *
  * Updated: Chad Sellers <csellers@tresys.com>
  *
  *  Added validation of kernel classes and permissions
  *
- * Copyright (C) 2006 Hewlett-Packard Development Company, L.P.
+ * Copyright (C) 2006, 2007 Hewlett-Packard Development Company, L.P.
  * Copyright (C) 2004-2006 Trusted Computer Solutions, Inc.
  * Copyright (C) 2003 - 2004, 2006 Tresys Technology, LLC
  * Copyright (C) 2003 Red Hat, Inc., James Morris <jmorris@redhat.com>
@@ -59,6 +60,8 @@
 extern void selnl_notify_policyload(u32 seqno);
 unsigned int policydb_loaded_version;
 
+int selinux_policycap_netpeer;
+
 /*
  * This is declared in avc.c
  */
@@ -292,6 +295,7 @@ static int context_struct_compute_av(struct context *scontext,
        struct class_datum *tclass_datum;
        struct ebitmap *sattr, *tattr;
        struct ebitmap_node *snode, *tnode;
+       const struct selinux_class_perm *kdefs = &selinux_class_perm;
        unsigned int i, j;
 
        /*
@@ -305,13 +309,6 @@ static int context_struct_compute_av(struct context *scontext,
                    tclass <= SECCLASS_NETLINK_DNRT_SOCKET)
                        tclass = SECCLASS_NETLINK_SOCKET;
 
-       if (!tclass || tclass > policydb.p_classes.nprim) {
-               printk(KERN_ERR "security_compute_av:  unrecognized class %d\n",
-                      tclass);
-               return -EINVAL;
-       }
-       tclass_datum = policydb.class_val_to_struct[tclass - 1];
-
        /*
         * Initialize the access vectors to the default values.
         */
@@ -321,6 +318,36 @@ static int context_struct_compute_av(struct context *scontext,
        avd->auditdeny = 0xffffffff;
        avd->seqno = latest_granting;
 
+       /*
+        * Check for all the invalid cases.
+        * - tclass 0
+        * - tclass > policy and > kernel
+        * - tclass > policy but is a userspace class
+        * - tclass > policy but we do not allow unknowns
+        */
+       if (unlikely(!tclass))
+               goto inval_class;
+       if (unlikely(tclass > policydb.p_classes.nprim))
+               if (tclass > kdefs->cts_len ||
+                   !kdefs->class_to_string[tclass - 1] ||
+                   !policydb.allow_unknown)
+                       goto inval_class;
+
+       /*
+        * Kernel class and we allow unknown so pad the allow decision
+        * the pad will be all 1 for unknown classes.
+        */
+       if (tclass <= kdefs->cts_len && policydb.allow_unknown)
+               avd->allowed = policydb.undefined_perms[tclass - 1];
+
+       /*
+        * Not in policy. Since decision is completed (all 1 or all 0) return.
+        */
+       if (unlikely(tclass > policydb.p_classes.nprim))
+               return 0;
+
+       tclass_datum = policydb.class_val_to_struct[tclass - 1];
+
        /*
         * If a specific type enforcement rule was defined for
         * this permission check, then use it.
@@ -329,12 +356,8 @@ static int context_struct_compute_av(struct context *scontext,
        avkey.specified = AVTAB_AV;
        sattr = &policydb.type_attr_map[scontext->type - 1];
        tattr = &policydb.type_attr_map[tcontext->type - 1];
-       ebitmap_for_each_bit(sattr, snode, i) {
-               if (!ebitmap_node_get_bit(snode, i))
-                       continue;
-               ebitmap_for_each_bit(tattr, tnode, j) {
-                       if (!ebitmap_node_get_bit(tnode, j))
-                               continue;
+       ebitmap_for_each_positive_bit(sattr, snode, i) {
+               ebitmap_for_each_positive_bit(tattr, tnode, j) {
                        avkey.source_type = i + 1;
                        avkey.target_type = j + 1;
                        for (node = avtab_search_node(&policydb.te_avtab, &avkey);
@@ -387,6 +410,10 @@ static int context_struct_compute_av(struct context *scontext,
        }
 
        return 0;
+
+inval_class:
+       printk(KERN_ERR "%s:  unrecognized class %d\n", __FUNCTION__, tclass);
+       return -EINVAL;
 }
 
 static int security_validtrans_handle_fail(struct context *ocontext,
@@ -1054,6 +1081,13 @@ static int validate_classes(struct policydb *p)
        const char *def_class, *def_perm, *pol_class;
        struct symtab *perms;
 
+       if (p->allow_unknown) {
+               u32 num_classes = kdefs->cts_len;
+               p->undefined_perms = kcalloc(num_classes, sizeof(u32), GFP_KERNEL);
+               if (!p->undefined_perms)
+                       return -ENOMEM;
+       }
+
        for (i = 1; i < kdefs->cts_len; i++) {
                def_class = kdefs->class_to_string[i];
                if (!def_class)
@@ -1062,6 +1096,10 @@ static int validate_classes(struct policydb *p)
                        printk(KERN_INFO
                               "security:  class %s not defined in policy\n",
                               def_class);
+                       if (p->reject_unknown)
+                               return -EINVAL;
+                       if (p->allow_unknown)
+                               p->undefined_perms[i-1] = ~0U;
                        continue;
                }
                pol_class = p->p_class_val_to_name[i-1];
@@ -1087,12 +1125,16 @@ static int validate_classes(struct policydb *p)
                        printk(KERN_INFO
                               "security:  permission %s in class %s not defined in policy\n",
                               def_perm, pol_class);
+                       if (p->reject_unknown)
+                               return -EINVAL;
+                       if (p->allow_unknown)
+                               p->undefined_perms[class_val-1] |= perm_val;
                        continue;
                }
                perdatum = hashtab_search(perms->table, def_perm);
                if (perdatum == NULL) {
                        printk(KERN_ERR
-                              "security:  permission %s in class %s not found in policy\n",
+                              "security:  permission %s in class %s not found in policy, bad policy\n",
                               def_perm, pol_class);
                        return -EINVAL;
                }
@@ -1130,12 +1172,16 @@ static int validate_classes(struct policydb *p)
                                printk(KERN_INFO
                                       "security:  permission %s in class %s not defined in policy\n",
                                       def_perm, pol_class);
+                               if (p->reject_unknown)
+                                       return -EINVAL;
+                               if (p->allow_unknown)
+                                       p->undefined_perms[class_val-1] |= (1 << j);
                                continue;
                        }
                        perdatum = hashtab_search(perms->table, def_perm);
                        if (perdatum == NULL) {
                                printk(KERN_ERR
-                                      "security:  permission %s in class %s not found in policy\n",
+                                      "security:  permission %s in class %s not found in policy, bad policy\n",
                                       def_perm, pol_class);
                                return -EINVAL;
                        }
@@ -1256,6 +1302,12 @@ bad:
        goto out;
 }
 
+static void security_load_policycaps(void)
+{
+       selinux_policycap_netpeer = ebitmap_get_bit(&policydb.policycaps,
+                                                 POLICYDB_CAPABILITY_NETPEER);
+}
+
 extern void selinux_complete_init(void);
 static int security_preserve_bools(struct policydb *p);
 
@@ -1303,6 +1355,7 @@ int security_load_policy(void *data, size_t len)
                        avtab_cache_destroy();
                        return -EINVAL;
                }
+               security_load_policycaps();
                policydb_loaded_version = policydb.policyvers;
                ss_initialized = 1;
                seqno = ++latest_granting;
@@ -1361,6 +1414,7 @@ int security_load_policy(void *data, size_t len)
        POLICY_WRLOCK;
        memcpy(&policydb, &newpolicydb, sizeof policydb);
        sidtab_set(&sidtab, &newsidtab);
+       security_load_policycaps();
        seqno = ++latest_granting;
        policydb_loaded_version = policydb.policyvers;
        POLICY_WRUNLOCK;
@@ -1435,11 +1489,8 @@ out:
  * security_netif_sid - Obtain the SID for a network interface.
  * @name: interface name
  * @if_sid: interface SID
- * @msg_sid: default SID for received packets
  */
-int security_netif_sid(char *name,
-                      u32 *if_sid,
-                      u32 *msg_sid)
+int security_netif_sid(char *name, u32 *if_sid)
 {
        int rc = 0;
        struct ocontext *c;
@@ -1467,11 +1518,8 @@ int security_netif_sid(char *name,
                                goto out;
                }
                *if_sid = c->sid[0];
-               *msg_sid = c->sid[1];
-       } else {
+       } else
                *if_sid = SECINITSID_NETIF;
-               *msg_sid = SECINITSID_NETMSG;
-       }
 
 out:
        POLICY_RDUNLOCK;
@@ -1621,14 +1669,10 @@ int security_get_user_sids(u32 fromsid,
                goto out_unlock;
        }
 
-       ebitmap_for_each_bit(&user->roles, rnode, i) {
-               if (!ebitmap_node_get_bit(rnode, i))
-                       continue;
+       ebitmap_for_each_positive_bit(&user->roles, rnode, i) {
                role = policydb.role_val_to_struct[i];
                usercon.role = i+1;
-               ebitmap_for_each_bit(&role->types, tnode, j) {
-                       if (!ebitmap_node_get_bit(tnode, j))
-                               continue;
+               ebitmap_for_each_positive_bit(&role->types, tnode, j) {
                        usercon.type = j+1;
 
                        if (mls_setup_user_range(fromcon, user, &usercon))
@@ -1705,6 +1749,9 @@ int security_genfs_sid(const char *fstype,
        struct ocontext *c;
        int rc = 0, cmp = 0;
 
+       while (path[0] == '/' && path[1] == '/')
+               path++;
+
        POLICY_RDLOCK;
 
        for (genfs = policydb.genfs; genfs; genfs = genfs->next) {
@@ -1858,11 +1905,12 @@ int security_set_bools(int len, int *values)
                if (!!values[i] != policydb.bool_val_to_struct[i]->state) {
                        audit_log(current->audit_context, GFP_ATOMIC,
                                AUDIT_MAC_CONFIG_CHANGE,
-                               "bool=%s val=%d old_val=%d auid=%u",
+                               "bool=%s val=%d old_val=%d auid=%u ses=%u",
                                policydb.p_bool_val_to_name[i],
                                !!values[i],
                                policydb.bool_val_to_struct[i]->state,
-                               audit_get_loginuid(current->audit_context));
+                               audit_get_loginuid(current),
+                               audit_get_sessionid(current));
                }
                if (values[i]) {
                        policydb.bool_val_to_struct[i]->state = 1;
@@ -2007,6 +2055,91 @@ out:
        return rc;
 }
 
+/**
+ * security_net_peersid_resolve - Compare and resolve two network peer SIDs
+ * @nlbl_sid: NetLabel SID
+ * @nlbl_type: NetLabel labeling protocol type
+ * @xfrm_sid: XFRM SID
+ *
+ * Description:
+ * Compare the @nlbl_sid and @xfrm_sid values and if the two SIDs can be
+ * resolved into a single SID it is returned via @peer_sid and the function
+ * returns zero.  Otherwise @peer_sid is set to SECSID_NULL and the function
+ * returns a negative value.  A table summarizing the behavior is below:
+ *
+ *                                 | function return |      @sid
+ *   ------------------------------+-----------------+-----------------
+ *   no peer labels                |        0        |    SECSID_NULL
+ *   single peer label             |        0        |    <peer_label>
+ *   multiple, consistent labels   |        0        |    <peer_label>
+ *   multiple, inconsistent labels |    -<errno>     |    SECSID_NULL
+ *
+ */
+int security_net_peersid_resolve(u32 nlbl_sid, u32 nlbl_type,
+                                u32 xfrm_sid,
+                                u32 *peer_sid)
+{
+       int rc;
+       struct context *nlbl_ctx;
+       struct context *xfrm_ctx;
+
+       /* handle the common (which also happens to be the set of easy) cases
+        * right away, these two if statements catch everything involving a
+        * single or absent peer SID/label */
+       if (xfrm_sid == SECSID_NULL) {
+               *peer_sid = nlbl_sid;
+               return 0;
+       }
+       /* NOTE: an nlbl_type == NETLBL_NLTYPE_UNLABELED is a "fallback" label
+        * and is treated as if nlbl_sid == SECSID_NULL when a XFRM SID/label
+        * is present */
+       if (nlbl_sid == SECSID_NULL || nlbl_type == NETLBL_NLTYPE_UNLABELED) {
+               *peer_sid = xfrm_sid;
+               return 0;
+       }
+
+       /* we don't need to check ss_initialized here since the only way both
+        * nlbl_sid and xfrm_sid are not equal to SECSID_NULL would be if the
+        * security server was initialized and ss_initialized was true */
+       if (!selinux_mls_enabled) {
+               *peer_sid = SECSID_NULL;
+               return 0;
+       }
+
+       POLICY_RDLOCK;
+
+       nlbl_ctx = sidtab_search(&sidtab, nlbl_sid);
+       if (!nlbl_ctx) {
+               printk(KERN_ERR
+                      "security_sid_mls_cmp:  unrecognized SID %d\n",
+                      nlbl_sid);
+               rc = -EINVAL;
+               goto out_slowpath;
+       }
+       xfrm_ctx = sidtab_search(&sidtab, xfrm_sid);
+       if (!xfrm_ctx) {
+               printk(KERN_ERR
+                      "security_sid_mls_cmp:  unrecognized SID %d\n",
+                      xfrm_sid);
+               rc = -EINVAL;
+               goto out_slowpath;
+       }
+       rc = (mls_context_cmp(nlbl_ctx, xfrm_ctx) ? 0 : -EACCES);
+
+out_slowpath:
+       POLICY_RDUNLOCK;
+       if (rc == 0)
+               /* at present NetLabel SIDs/labels really only carry MLS
+                * information so if the MLS portion of the NetLabel SID
+                * matches the MLS portion of the labeled XFRM SID/label
+                * then pass along the XFRM SID as it is the most
+                * expressive */
+               *peer_sid = xfrm_sid;
+       else
+               *peer_sid = SECSID_NULL;
+       return rc;
+}
+
 static int get_classes_callback(void *k, void *d, void *args)
 {
        struct class_datum *datum = d;
@@ -2102,6 +2235,37 @@ err:
        return rc;
 }
 
+int security_get_reject_unknown(void)
+{
+       return policydb.reject_unknown;
+}
+
+int security_get_allow_unknown(void)
+{
+       return policydb.allow_unknown;
+}
+
+/**
+ * security_policycap_supported - Check for a specific policy capability
+ * @req_cap: capability
+ *
+ * Description:
+ * This function queries the currently loaded policy to see if it supports the
+ * capability specified by @req_cap.  Returns true (1) if the capability is
+ * supported, false (0) if it isn't supported.
+ *
+ */
+int security_policycap_supported(unsigned int req_cap)
+{
+       int rc;
+
+       POLICY_RDLOCK;
+       rc = ebitmap_get_bit(&policydb.policycaps, req_cap);
+       POLICY_RDUNLOCK;
+
+       return rc;
+}
+
 struct selinux_audit_rule {
        u32 au_seqno;
        struct context au_ctxt;
@@ -2351,50 +2515,10 @@ void selinux_audit_set_callback(int (*callback)(void))
 }
 
 #ifdef CONFIG_NETLABEL
-/*
- * NetLabel cache structure
- */
-#define NETLBL_CACHE(x)           ((struct selinux_netlbl_cache *)(x))
-#define NETLBL_CACHE_T_NONE       0
-#define NETLBL_CACHE_T_SID        1
-#define NETLBL_CACHE_T_MLS        2
-struct selinux_netlbl_cache {
-       u32 type;
-       union {
-               u32 sid;
-               struct mls_range mls_label;
-       } data;
-};
-
-/**
- * security_netlbl_cache_free - Free the NetLabel cached data
- * @data: the data to free
- *
- * Description:
- * This function is intended to be used as the free() callback inside the
- * netlbl_lsm_cache structure.
- *
- */
-static void security_netlbl_cache_free(const void *data)
-{
-       struct selinux_netlbl_cache *cache;
-
-       if (data == NULL)
-               return;
-
-       cache = NETLBL_CACHE(data);
-       switch (cache->type) {
-       case NETLBL_CACHE_T_MLS:
-               ebitmap_destroy(&cache->data.mls_label.level[0].cat);
-               break;
-       }
-       kfree(data);
-}
-
 /**
  * security_netlbl_cache_add - Add an entry to the NetLabel cache
  * @secattr: the NetLabel packet security attributes
- * @ctx: the SELinux context
+ * @sid: the SELinux SID
  *
  * Description:
  * Attempt to cache the context in @ctx, which was derived from the packet in
@@ -2403,60 +2527,46 @@ static void security_netlbl_cache_free(const void *data)
  *
  */
 static void security_netlbl_cache_add(struct netlbl_lsm_secattr *secattr,
-                                     struct context *ctx)
+                                     u32 sid)
 {
-       struct selinux_netlbl_cache *cache = NULL;
+       u32 *sid_cache;
 
-       secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
-       if (secattr->cache == NULL)
+       sid_cache = kmalloc(sizeof(*sid_cache), GFP_ATOMIC);
+       if (sid_cache == NULL)
                return;
-
-       cache = kzalloc(sizeof(*cache), GFP_ATOMIC);
-       if (cache == NULL)
-               return;
-
-       cache->type = NETLBL_CACHE_T_MLS;
-       if (ebitmap_cpy(&cache->data.mls_label.level[0].cat,
-                       &ctx->range.level[0].cat) != 0) {
-               kfree(cache);
+       secattr->cache = netlbl_secattr_cache_alloc(GFP_ATOMIC);
+       if (secattr->cache == NULL) {
+               kfree(sid_cache);
                return;
        }
-       cache->data.mls_label.level[1].cat.highbit =
-               cache->data.mls_label.level[0].cat.highbit;
-       cache->data.mls_label.level[1].cat.node =
-               cache->data.mls_label.level[0].cat.node;
-       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 = security_netlbl_cache_free;
-       secattr->cache->data = (void *)cache;
+       *sid_cache = sid;
+       secattr->cache->free = kfree;
+       secattr->cache->data = sid_cache;
        secattr->flags |= NETLBL_SECATTR_CACHE;
 }
 
 /**
  * security_netlbl_secattr_to_sid - Convert a NetLabel secattr to a SELinux SID
  * @secattr: the NetLabel packet security attributes
- * @base_sid: the SELinux SID to use as a context for MLS only attributes
  * @sid: the SELinux SID
  *
  * Description:
  * Convert the given NetLabel security attributes in @secattr into a
  * SELinux SID.  If the @secattr field does not contain a full SELinux
- * SID/context then use the context in @base_sid as the foundation.  If
- * possibile the 'cache' field of @secattr is set and the CACHE flag is set;
- * this is to allow the @secattr to be used by NetLabel to cache the secattr to
- * SID conversion for future lookups.  Returns zero on success, negative
- * values on failure.
+ * SID/context then use SECINITSID_NETMSG as the foundation.  If possibile the
+ * 'cache' field of @secattr is set and the CACHE flag is set; this is to
+ * allow the @secattr to be used by NetLabel to cache the secattr to SID
+ * conversion for future lookups.  Returns zero on success, negative values on
+ * failure.
  *
  */
 int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
-                                  u32 base_sid,
                                   u32 *sid)
 {
        int rc = -EIDRM;
        struct context *ctx;
        struct context ctx_new;
-       struct selinux_netlbl_cache *cache;
 
        if (!ss_initialized) {
                *sid = SECSID_NULL;
@@ -2466,40 +2576,13 @@ int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
        POLICY_RDLOCK;
 
        if (secattr->flags & NETLBL_SECATTR_CACHE) {
-               cache = NETLBL_CACHE(secattr->cache->data);
-               switch (cache->type) {
-               case NETLBL_CACHE_T_SID:
-                       *sid = cache->data.sid;
-                       rc = 0;
-                       break;
-               case NETLBL_CACHE_T_MLS:
-                       ctx = sidtab_search(&sidtab, base_sid);
-                       if (ctx == NULL)
-                               goto netlbl_secattr_to_sid_return;
-
-                       ctx_new.user = ctx->user;
-                       ctx_new.role = ctx->role;
-                       ctx_new.type = ctx->type;
-                       ctx_new.range.level[0].sens =
-                               cache->data.mls_label.level[0].sens;
-                       ctx_new.range.level[0].cat.highbit =
-                               cache->data.mls_label.level[0].cat.highbit;
-                       ctx_new.range.level[0].cat.node =
-                               cache->data.mls_label.level[0].cat.node;
-                       ctx_new.range.level[1].sens =
-                               cache->data.mls_label.level[1].sens;
-                       ctx_new.range.level[1].cat.highbit =
-                               cache->data.mls_label.level[1].cat.highbit;
-                       ctx_new.range.level[1].cat.node =
-                               cache->data.mls_label.level[1].cat.node;
-
-                       rc = sidtab_context_to_sid(&sidtab, &ctx_new, sid);
-                       break;
-               default:
-                       goto netlbl_secattr_to_sid_return;
-               }
+               *sid = *(u32 *)secattr->cache->data;
+               rc = 0;
+       } else if (secattr->flags & NETLBL_SECATTR_SECID) {
+               *sid = secattr->attr.secid;
+               rc = 0;
        } else if (secattr->flags & NETLBL_SECATTR_MLS_LVL) {
-               ctx = sidtab_search(&sidtab, base_sid);
+               ctx = sidtab_search(&sidtab, SECINITSID_NETMSG);
                if (ctx == NULL)
                        goto netlbl_secattr_to_sid_return;
 
@@ -2509,7 +2592,7 @@ int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
                mls_import_netlbl_lvl(&ctx_new, secattr);
                if (secattr->flags & NETLBL_SECATTR_MLS_CAT) {
                        if (ebitmap_netlbl_import(&ctx_new.range.level[0].cat,
-                                                 secattr->mls_cat) != 0)
+                                                 secattr->attr.mls.cat) != 0)
                                goto netlbl_secattr_to_sid_return;
                        ctx_new.range.level[1].cat.highbit =
                                ctx_new.range.level[0].cat.highbit;
@@ -2526,7 +2609,7 @@ int security_netlbl_secattr_to_sid(struct netlbl_lsm_secattr *secattr,
                if (rc != 0)
                        goto netlbl_secattr_to_sid_return_cleanup;
 
-               security_netlbl_cache_add(secattr, &ctx_new);
+               security_netlbl_cache_add(secattr, *sid);
 
                ebitmap_destroy(&ctx_new.range.level[0].cat);
        } else {
@@ -2557,8 +2640,6 @@ int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
        int rc = -ENOENT;
        struct context *ctx;
 
-       netlbl_secattr_init(secattr);
-
        if (!ss_initialized)
                return 0;
 
@@ -2579,7 +2660,6 @@ int security_netlbl_sid_to_secattr(u32 sid, struct netlbl_lsm_secattr *secattr)
 
 netlbl_sid_to_secattr_failure:
        POLICY_RDUNLOCK;
-       netlbl_secattr_destroy(secattr);
        return rc;
 }
 #endif /* CONFIG_NETLABEL */