[NetLabel]: rework the Netlink attribute handling (part 1)
[deliverable/linux.git] / net / ipv4 / cipso_ipv4.c
index 87e71563335d61fb0f551b6b62e4196a8cd1bea9..e6ce0b3ba62a49ed8aef7ae0c6f4541a67a3d53d 100644 (file)
@@ -530,197 +530,42 @@ struct cipso_v4_doi *cipso_v4_doi_getdef(u32 doi)
 }
 
 /**
- * cipso_v4_doi_dump_all - Dump all the CIPSO DOI definitions into a sk_buff
- * @headroom: the amount of headroom to allocate for the sk_buff
+ * cipso_v4_doi_walk - Iterate through the DOI definitions
+ * @skip_cnt: skip past this number of DOI definitions, updated
+ * @callback: callback for each DOI definition
+ * @cb_arg: argument for the callback function
  *
  * Description:
- * Dump a list of all the configured DOI values into a sk_buff.  The returned
- * sk_buff has room at the front of the sk_buff for @headroom bytes.  See
- * net/netlabel/netlabel_cipso_v4.h for the LISTALL message format.  This
- * function may fail if another process is changing the DOI list at the same
- * time.  Returns a pointer to a sk_buff on success, NULL on error.
+ * Iterate over the DOI definition list, skipping the first @skip_cnt entries.
+ * For each entry call @callback, if @callback returns a negative value stop
+ * 'walking' through the list and return.  Updates the value in @skip_cnt upon
+ * return.  Returns zero on success, negative values on failure.
  *
  */
-struct sk_buff *cipso_v4_doi_dump_all(size_t headroom)
+int cipso_v4_doi_walk(u32 *skip_cnt,
+                    int (*callback) (struct cipso_v4_doi *doi_def, void *arg),
+                    void *cb_arg)
 {
-       struct sk_buff *skb = NULL;
-       struct cipso_v4_doi *iter;
+       int ret_val = -ENOENT;
        u32 doi_cnt = 0;
-       ssize_t buf_len;
-
-       buf_len = NETLBL_LEN_U32;
-       rcu_read_lock();
-       list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
-               if (iter->valid) {
-                       doi_cnt += 1;
-                       buf_len += 2 * NETLBL_LEN_U32;
-               }
-
-       skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
-       if (skb == NULL)
-               goto doi_dump_all_failure;
-
-       if (nla_put_u32(skb, NLA_U32, doi_cnt) != 0)
-               goto doi_dump_all_failure;
-       buf_len -= NETLBL_LEN_U32;
-       list_for_each_entry_rcu(iter, &cipso_v4_doi_list, list)
-               if (iter->valid) {
-                       if (buf_len < 2 * NETLBL_LEN_U32)
-                               goto doi_dump_all_failure;
-                       if (nla_put_u32(skb, NLA_U32, iter->doi) != 0)
-                               goto doi_dump_all_failure;
-                       if (nla_put_u32(skb, NLA_U32, iter->type) != 0)
-                               goto doi_dump_all_failure;
-                       buf_len -= 2 * NETLBL_LEN_U32;
-               }
-       rcu_read_unlock();
-
-       return skb;
-
-doi_dump_all_failure:
-       rcu_read_unlock();
-       kfree(skb);
-       return NULL;
-}
-
-/**
- * cipso_v4_doi_dump - Dump a CIPSO DOI definition into a sk_buff
- * @doi: the DOI value
- * @headroom: the amount of headroom to allocate for the sk_buff
- *
- * Description:
- * Lookup the DOI definition matching @doi and dump it's contents into a
- * sk_buff.  The returned sk_buff has room at the front of the sk_buff for
- * @headroom bytes.  See net/netlabel/netlabel_cipso_v4.h for the LIST message
- * format.  This function may fail if another process is changing the DOI list
- * at the same time.  Returns a pointer to a sk_buff on success, NULL on error.
- *
- */
-struct sk_buff *cipso_v4_doi_dump(u32 doi, size_t headroom)
-{
-       struct sk_buff *skb = NULL;
-       struct cipso_v4_doi *iter;
-       u32 tag_cnt = 0;
-       u32 lvl_cnt = 0;
-       u32 cat_cnt = 0;
-       ssize_t buf_len;
-       ssize_t tmp;
+       struct cipso_v4_doi *iter_doi;
 
        rcu_read_lock();
-       iter = cipso_v4_doi_getdef(doi);
-       if (iter == NULL)
-               goto doi_dump_failure;
-       buf_len = NETLBL_LEN_U32;
-       switch (iter->type) {
-       case CIPSO_V4_MAP_PASS:
-               buf_len += NETLBL_LEN_U32;
-               while(tag_cnt < CIPSO_V4_TAG_MAXCNT &&
-                     iter->tags[tag_cnt] != CIPSO_V4_TAG_INVALID) {
-                       tag_cnt += 1;
-                       buf_len += NETLBL_LEN_U8;
-               }
-               break;
-       case CIPSO_V4_MAP_STD:
-               buf_len += 3 * NETLBL_LEN_U32;
-               while (tag_cnt < CIPSO_V4_TAG_MAXCNT &&
-                      iter->tags[tag_cnt] != CIPSO_V4_TAG_INVALID) {
-                       tag_cnt += 1;
-                       buf_len += NETLBL_LEN_U8;
-               }
-               for (tmp = 0; tmp < iter->map.std->lvl.local_size; tmp++)
-                       if (iter->map.std->lvl.local[tmp] !=
-                           CIPSO_V4_INV_LVL) {
-                               lvl_cnt += 1;
-                               buf_len += NETLBL_LEN_U32 + NETLBL_LEN_U8;
+       list_for_each_entry_rcu(iter_doi, &cipso_v4_doi_list, list)
+               if (iter_doi->valid) {
+                       if (doi_cnt++ < *skip_cnt)
+                               continue;
+                       ret_val = callback(iter_doi, cb_arg);
+                       if (ret_val < 0) {
+                               doi_cnt--;
+                               goto doi_walk_return;
                        }
-               for (tmp = 0; tmp < iter->map.std->cat.local_size; tmp++)
-                       if (iter->map.std->cat.local[tmp] !=
-                           CIPSO_V4_INV_CAT) {
-                               cat_cnt += 1;
-                               buf_len += NETLBL_LEN_U32 + NETLBL_LEN_U16;
-                       }
-               break;
-       }
-
-       skb = netlbl_netlink_alloc_skb(headroom, buf_len, GFP_ATOMIC);
-       if (skb == NULL)
-               goto doi_dump_failure;
-
-       if (nla_put_u32(skb, NLA_U32, iter->type) != 0)
-               goto doi_dump_failure;
-       buf_len -= NETLBL_LEN_U32;
-       if (iter != cipso_v4_doi_getdef(doi))
-               goto doi_dump_failure;
-       switch (iter->type) {
-       case CIPSO_V4_MAP_PASS:
-               if (nla_put_u32(skb, NLA_U32, tag_cnt) != 0)
-                       goto doi_dump_failure;
-               buf_len -= NETLBL_LEN_U32;
-               for (tmp = 0;
-                    tmp < CIPSO_V4_TAG_MAXCNT &&
-                            iter->tags[tmp] != CIPSO_V4_TAG_INVALID;
-                    tmp++) {
-                       if (buf_len < NETLBL_LEN_U8)
-                               goto doi_dump_failure;
-                       if (nla_put_u8(skb, NLA_U8, iter->tags[tmp]) != 0)
-                               goto doi_dump_failure;
-                       buf_len -= NETLBL_LEN_U8;
                }
-               break;
-       case CIPSO_V4_MAP_STD:
-               if (nla_put_u32(skb, NLA_U32, tag_cnt) != 0)
-                       goto doi_dump_failure;
-               if (nla_put_u32(skb, NLA_U32, lvl_cnt) != 0)
-                       goto doi_dump_failure;
-               if (nla_put_u32(skb, NLA_U32, cat_cnt) != 0)
-                       goto doi_dump_failure;
-               buf_len -= 3 * NETLBL_LEN_U32;
-               for (tmp = 0;
-                    tmp < CIPSO_V4_TAG_MAXCNT &&
-                            iter->tags[tmp] != CIPSO_V4_TAG_INVALID;
-                    tmp++) {
-                       if (buf_len < NETLBL_LEN_U8)
-                               goto doi_dump_failure;
-                       if (nla_put_u8(skb, NLA_U8, iter->tags[tmp]) != 0)
-                               goto doi_dump_failure;
-                       buf_len -= NETLBL_LEN_U8;
-               }
-               for (tmp = 0; tmp < iter->map.std->lvl.local_size; tmp++)
-                       if (iter->map.std->lvl.local[tmp] !=
-                           CIPSO_V4_INV_LVL) {
-                               if (buf_len < NETLBL_LEN_U32 + NETLBL_LEN_U8)
-                                       goto doi_dump_failure;
-                               if (nla_put_u32(skb, NLA_U32, tmp) != 0)
-                                       goto doi_dump_failure;
-                               if (nla_put_u8(skb,
-                                          NLA_U8,
-                                          iter->map.std->lvl.local[tmp]) != 0)
-                                       goto doi_dump_failure;
-                               buf_len -= NETLBL_LEN_U32 + NETLBL_LEN_U8;
-                       }
-               for (tmp = 0; tmp < iter->map.std->cat.local_size; tmp++)
-                       if (iter->map.std->cat.local[tmp] !=
-                           CIPSO_V4_INV_CAT) {
-                               if (buf_len < NETLBL_LEN_U32 + NETLBL_LEN_U16)
-                                       goto doi_dump_failure;
-                               if (nla_put_u32(skb, NLA_U32, tmp) != 0)
-                                       goto doi_dump_failure;
-                               if (nla_put_u16(skb,
-                                          NLA_U16,
-                                          iter->map.std->cat.local[tmp]) != 0)
-                                       goto doi_dump_failure;
-                               buf_len -= NETLBL_LEN_U32 + NETLBL_LEN_U16;
-                       }
-               break;
-       }
-       rcu_read_unlock();
-
-       return skb;
 
-doi_dump_failure:
+doi_walk_return:
        rcu_read_unlock();
-       kfree(skb);
-       return NULL;
+       *skip_cnt = doi_cnt;
+       return ret_val;
 }
 
 /**
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