smack: Add a new '-CIPSO' option to the network address label configuration

[linux-2.6-omap-h63xx.git] / security / smack / smackfs.c

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 856c8a2875231f2a6d64075bb114f99e0c356628..e03a7e19c73b3a0b49d7533db45ecb719d250f30 100644 (file)
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -86,6 +86,9 @@ LIST_HEAD(smack_rule_list);
 
 static int smk_cipso_doi_value = SMACK_CIPSO_DOI_DEFAULT;
 
+const char *smack_cipso_option = SMACK_CIPSO_OPTION;
+
+
 #define        SEQ_READ_FINISHED       1
 
 /*
@@ -565,6 +568,11 @@ static ssize_t smk_write_cipso(struct file *file, const char __user *buf,
                goto unlockedout;
        }
 
+       /* labels cannot begin with a '-' */
+       if (data[0] == '-') {
+               rc = -EINVAL;
+               goto unlockedout;
+       }
        data[count] = '\0';
        rule = data;
        /*
@@ -808,9 +816,18 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
        if (m > BEBITS)
                return -EINVAL;
 
-       sp = smk_import(smack, 0);
-       if (sp == NULL)
-               return -EINVAL;
+       /* if smack begins with '-', its an option, don't import it */
+       if (smack[0] != '-') {
+               sp = smk_import(smack, 0);
+               if (sp == NULL)
+                       return -EINVAL;
+       } else {
+               /* check known options */
+               if (strcmp(smack, smack_cipso_option) == 0)
+                       sp = (char *)smack_cipso_option;
+               else
+                       return -EINVAL;
+       }
 
        for (temp_mask = 0; m > 0; m--) {
                temp_mask |= mask_bits;
@@ -849,18 +866,23 @@ static ssize_t smk_write_netlbladdr(struct file *file, const char __user *buf,
                        smk_netlbladdr_insert(skp);
                }
        } else {
-               rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
-                       &skp->smk_host.sin_addr, &skp->smk_mask,
-                       PF_INET, &audit_info);
+               /* we delete the unlabeled entry, only if the previous label
+                * wasnt the special CIPSO option */
+               if (skp->smk_label != smack_cipso_option)
+                       rc = netlbl_cfg_unlbl_static_del(&init_net, NULL,
+                                       &skp->smk_host.sin_addr, &skp->smk_mask,
+                                       PF_INET, &audit_info);
+               else
+                       rc = 0;
                skp->smk_label = sp;
        }
 
        /*
         * Now tell netlabel about the single label nature of
         * this host so that incoming packets get labeled.
+        * but only if we didn't get the special CIPSO option
         */
-
-       if (rc == 0)
+       if (rc == 0 && sp != smack_cipso_option)
                rc = netlbl_cfg_unlbl_static_add(&init_net, NULL,
                        &skp->smk_host.sin_addr, &skp->smk_mask, PF_INET,
                        smack_to_secid(skp->smk_label), &audit_info);