NetLabel: convert the unlabeled accept flag to use RCU
[safe/jmp/linux-2.6] / net / netlabel / netlabel_domainhash.c
index 5bb3fad..af4371d 100644 (file)
 #include <linux/skbuff.h>
 #include <linux/spinlock.h>
 #include <linux/string.h>
+#include <linux/audit.h>
 #include <net/netlabel.h>
 #include <net/cipso_ipv4.h>
 #include <asm/bug.h>
 
 #include "netlabel_mgmt.h"
 #include "netlabel_domainhash.h"
+#include "netlabel_user.h"
 
 struct netlbl_domhsh_tbl {
        struct list_head *tbl;
@@ -50,11 +52,11 @@ struct netlbl_domhsh_tbl {
 /* Domain hash table */
 /* XXX - updates should be so rare that having one spinlock for the entire
  * hash table should be okay */
-DEFINE_SPINLOCK(netlbl_domhsh_lock);
+static DEFINE_SPINLOCK(netlbl_domhsh_lock);
 static struct netlbl_domhsh_tbl *netlbl_domhsh = NULL;
 
 /* Default domain mapping */
-DEFINE_SPINLOCK(netlbl_domhsh_def_lock);
+static DEFINE_SPINLOCK(netlbl_domhsh_def_lock);
 static struct netlbl_dom_map *netlbl_domhsh_def = NULL;
 
 /*
@@ -186,6 +188,7 @@ int netlbl_domhsh_init(u32 size)
 /**
  * netlbl_domhsh_add - Adds a entry to the domain hash table
  * @entry: the entry to add
+ * @audit_info: NetLabel audit information
  *
  * Description:
  * Adds a new entry to the domain hash table and handles any updates to the
@@ -193,10 +196,13 @@ int netlbl_domhsh_init(u32 size)
  * negative on failure.
  *
  */
-int netlbl_domhsh_add(struct netlbl_dom_map *entry)
+int netlbl_domhsh_add(struct netlbl_dom_map *entry,
+                     struct netlbl_audit *audit_info)
 {
        int ret_val;
        u32 bkt;
+       struct audit_buffer *audit_buf;
+       char *audit_domain;
 
        switch (entry->type) {
        case NETLBL_NLTYPE_UNLABELED:
@@ -236,6 +242,26 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry)
                spin_unlock(&netlbl_domhsh_def_lock);
        } else
                ret_val = -EINVAL;
+
+       if (entry->domain != NULL)
+               audit_domain = entry->domain;
+       else
+               audit_domain = "(default)";
+       audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_ADD, audit_info);
+       audit_log_format(audit_buf, " nlbl_domain=%s", audit_domain);
+       switch (entry->type) {
+       case NETLBL_NLTYPE_UNLABELED:
+               audit_log_format(audit_buf, " nlbl_protocol=unlbl");
+               break;
+       case NETLBL_NLTYPE_CIPSOV4:
+               audit_log_format(audit_buf,
+                                " nlbl_protocol=cipsov4 cipso_doi=%u",
+                                entry->type_def.cipsov4->doi);
+               break;
+       }
+       audit_log_format(audit_buf, " res=%u", ret_val == 0 ? 1 : 0);
+       audit_log_end(audit_buf);
+
        rcu_read_unlock();
 
        if (ret_val != 0) {
@@ -254,6 +280,7 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry)
 /**
  * netlbl_domhsh_add_default - Adds the default entry to the domain hash table
  * @entry: the entry to add
+ * @audit_info: NetLabel audit information
  *
  * Description:
  * Adds a new default entry to the domain hash table and handles any updates
@@ -261,14 +288,16 @@ int netlbl_domhsh_add(struct netlbl_dom_map *entry)
  * negative on failure.
  *
  */
-int netlbl_domhsh_add_default(struct netlbl_dom_map *entry)
+int netlbl_domhsh_add_default(struct netlbl_dom_map *entry,
+                             struct netlbl_audit *audit_info)
 {
-       return netlbl_domhsh_add(entry);
+       return netlbl_domhsh_add(entry, audit_info);
 }
 
 /**
  * netlbl_domhsh_remove - Removes an entry from the domain hash table
  * @domain: the domain to remove
+ * @audit_info: NetLabel audit information
  *
  * Description:
  * Removes an entry from the domain hash table and handles any updates to the
@@ -276,10 +305,12 @@ int netlbl_domhsh_add_default(struct netlbl_dom_map *entry)
  * negative on failure.
  *
  */
-int netlbl_domhsh_remove(const char *domain)
+int netlbl_domhsh_remove(const char *domain, struct netlbl_audit *audit_info)
 {
        int ret_val = -ENOENT;
        struct netlbl_dom_map *entry;
+       struct audit_buffer *audit_buf;
+       char *audit_domain;
 
        rcu_read_lock();
        if (domain != NULL)
@@ -316,6 +347,18 @@ int netlbl_domhsh_remove(const char *domain)
                        ret_val = -ENOENT;
                spin_unlock(&netlbl_domhsh_def_lock);
        }
+
+       if (entry->domain != NULL)
+               audit_domain = entry->domain;
+       else
+               audit_domain = "(default)";
+       audit_buf = netlbl_audit_start_common(AUDIT_MAC_MAP_DEL, audit_info);
+       audit_log_format(audit_buf,
+                        " nlbl_domain=%s res=%u",
+                        audit_domain,
+                        ret_val == 0 ? 1 : 0);
+       audit_log_end(audit_buf);
+
        if (ret_val == 0)
                call_rcu(&entry->rcu, netlbl_domhsh_free_entry);
 
@@ -326,6 +369,7 @@ remove_return:
 
 /**
  * netlbl_domhsh_remove_default - Removes the default entry from the table
+ * @audit_info: NetLabel audit information
  *
  * Description:
  * Removes/resets the default entry for the domain hash table and handles any
@@ -333,9 +377,9 @@ remove_return:
  * success, non-zero on failure.
  *
  */
-int netlbl_domhsh_remove_default(void)
+int netlbl_domhsh_remove_default(struct netlbl_audit *audit_info)
 {
-       return netlbl_domhsh_remove(NULL);
+       return netlbl_domhsh_remove(NULL, audit_info);
 }
 
 /**
@@ -354,160 +398,51 @@ struct netlbl_dom_map *netlbl_domhsh_getentry(const char *domain)
 }
 
 /**
- * netlbl_domhsh_dump - Dump the domain hash table into a sk_buff
+ * netlbl_domhsh_walk - Iterate through the domain mapping hash table
+ * @skip_bkt: the number of buckets to skip at the start
+ * @skip_chain: the number of entries to skip in the first iterated bucket
+ * @callback: callback for each entry
+ * @cb_arg: argument for the callback function
  *
  * Description:
- * Dump the domain hash table into a buffer suitable for returning to an
- * application in response to a NetLabel management DOMAIN message.  This
- * function may fail if another process is growing the hash table at the same
- * time.  The returned sk_buff has room at the front of the sk_buff for
- * @headroom bytes.  See netlabel.h for the DOMAIN message format.  Returns a
- * pointer to a sk_buff on success, NULL on error.
+ * Interate over the domain mapping hash table, skipping the first @skip_bkt
+ * buckets and @skip_chain entries.  For each entry in the table call
+ * @callback, if @callback returns a negative value stop 'walking' through the
+ * table and return.  Updates the values in @skip_bkt and @skip_chain on
+ * return.  Returns zero on succcess, negative values on failure.
  *
  */
-struct sk_buff *netlbl_domhsh_dump(size_t headroom)
+int netlbl_domhsh_walk(u32 *skip_bkt,
+                    u32 *skip_chain,
+                    int (*callback) (struct netlbl_dom_map *entry, void *arg),
+                    void *cb_arg)
 {
-       struct sk_buff *skb = NULL;
-       ssize_t buf_len;
-       u32 bkt_iter;
-       u32 dom_cnt = 0;
-       struct netlbl_domhsh_tbl *hsh_tbl;
-       struct netlbl_dom_map *list_iter;
-       ssize_t tmp_len;
+       int ret_val = -ENOENT;
+       u32 iter_bkt;
+       struct netlbl_dom_map *iter_entry;
+       u32 chain_cnt = 0;
 
-       buf_len = NETLBL_LEN_U32;
        rcu_read_lock();
-       hsh_tbl = rcu_dereference(netlbl_domhsh);
-       for (bkt_iter = 0; bkt_iter < hsh_tbl->size; bkt_iter++)
-               list_for_each_entry_rcu(list_iter,
-                                       &hsh_tbl->tbl[bkt_iter], list) {
-                       buf_len += NETLBL_LEN_U32 +
-                               nla_total_size(strlen(list_iter->domain) + 1);
-                       switch (list_iter->type) {
-                       case NETLBL_NLTYPE_UNLABELED:
-                               break;
-                       case NETLBL_NLTYPE_CIPSOV4:
-                               buf_len += 2 * NETLBL_LEN_U32;
-                               break;
-                       }
-                       dom_cnt++;
-               }
-
-       skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
-       if (skb == NULL)
-               goto dump_failure;
-
-       if (nla_put_u32(skb, NLA_U32, dom_cnt) != 0)
-               goto dump_failure;
-       buf_len -= NETLBL_LEN_U32;
-       hsh_tbl = rcu_dereference(netlbl_domhsh);
-       for (bkt_iter = 0; bkt_iter < hsh_tbl->size; bkt_iter++)
-               list_for_each_entry_rcu(list_iter,
-                                       &hsh_tbl->tbl[bkt_iter], list) {
-                       tmp_len = nla_total_size(strlen(list_iter->domain) +
-                                                1);
-                       if (buf_len < NETLBL_LEN_U32 + tmp_len)
-                               goto dump_failure;
-                       if (nla_put_string(skb,
-                                          NLA_STRING,
-                                          list_iter->domain) != 0)
-                               goto dump_failure;
-                       if (nla_put_u32(skb, NLA_U32, list_iter->type) != 0)
-                               goto dump_failure;
-                       buf_len -= NETLBL_LEN_U32 + tmp_len;
-                       switch (list_iter->type) {
-                       case NETLBL_NLTYPE_UNLABELED:
-                               break;
-                       case NETLBL_NLTYPE_CIPSOV4:
-                               if (buf_len < 2 * NETLBL_LEN_U32)
-                                       goto dump_failure;
-                               if (nla_put_u32(skb,
-                                      NLA_U32,
-                                      list_iter->type_def.cipsov4->type) != 0)
-                                       goto dump_failure;
-                               if (nla_put_u32(skb,
-                                      NLA_U32,
-                                      list_iter->type_def.cipsov4->doi) != 0)
-                                       goto dump_failure;
-                               buf_len -= 2 * NETLBL_LEN_U32;
-                               break;
+       for (iter_bkt = *skip_bkt;
+            iter_bkt < rcu_dereference(netlbl_domhsh)->size;
+            iter_bkt++, chain_cnt = 0) {
+               list_for_each_entry_rcu(iter_entry,
+                                       &netlbl_domhsh->tbl[iter_bkt],
+                                       list)
+                       if (iter_entry->valid) {
+                               if (chain_cnt++ < *skip_chain)
+                                       continue;
+                               ret_val = callback(iter_entry, cb_arg);
+                               if (ret_val < 0) {
+                                       chain_cnt--;
+                                       goto walk_return;
+                               }
                        }
-               }
-       rcu_read_unlock();
-
-       return skb;
-
-dump_failure:
-       rcu_read_unlock();
-       kfree_skb(skb);
-       return NULL;
-}
-
-/**
- * netlbl_domhsh_dump_default - Dump the default domain mapping into a sk_buff
- *
- * Description:
- * Dump the default domain mapping into a buffer suitable for returning to an
- * application in response to a NetLabel management DEFDOMAIN message.  This
- * function may fail if another process is changing the default domain mapping
- * at the same time.  The returned sk_buff has room at the front of the
- * skb_buff for @headroom bytes.  See netlabel.h for the DEFDOMAIN message
- * format.  Returns a pointer to a sk_buff on success, NULL on error.
- *
- */
-struct sk_buff *netlbl_domhsh_dump_default(size_t headroom)
-{
-       struct sk_buff *skb;
-       ssize_t buf_len;
-       struct netlbl_dom_map *entry;
-
-       buf_len = NETLBL_LEN_U32;
-       rcu_read_lock();
-       entry = rcu_dereference(netlbl_domhsh_def);
-       if (entry != NULL)
-               switch (entry->type) {
-               case NETLBL_NLTYPE_UNLABELED:
-                       break;
-               case NETLBL_NLTYPE_CIPSOV4:
-                       buf_len += 2 * NETLBL_LEN_U32;
-                       break;
-               }
-
-       skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
-       if (skb == NULL)
-               goto dump_default_failure;
-
-       if (entry != rcu_dereference(netlbl_domhsh_def))
-               goto dump_default_failure;
-       if (entry != NULL) {
-               if (nla_put_u32(skb, NLA_U32, entry->type) != 0)
-                       goto dump_default_failure;
-               buf_len -= NETLBL_LEN_U32;
-               switch (entry->type) {
-               case NETLBL_NLTYPE_UNLABELED:
-                       break;
-               case NETLBL_NLTYPE_CIPSOV4:
-                       if (buf_len < 2 * NETLBL_LEN_U32)
-                               goto dump_default_failure;
-                       if (nla_put_u32(skb,
-                                       NLA_U32,
-                                       entry->type_def.cipsov4->type) != 0)
-                               goto dump_default_failure;
-                       if (nla_put_u32(skb,
-                                       NLA_U32,
-                                       entry->type_def.cipsov4->doi) != 0)
-                               goto dump_default_failure;
-                       buf_len -= 2 * NETLBL_LEN_U32;
-                       break;
-               }
-       } else
-               nla_put_u32(skb, NLA_U32, NETLBL_NLTYPE_NONE);
-       rcu_read_unlock();
-
-       return skb;
+       }
 
-dump_default_failure:
+walk_return:
        rcu_read_unlock();
-       kfree_skb(skb);
-       return NULL;
+       *skip_bkt = iter_bkt;
+       *skip_chain = chain_cnt;
+       return ret_val;
 }