[NetLabel]: rework the Netlink attribute handling (part 1)
At the suggestion of Thomas Graf, rewrite NetLabel's use of Netlink attributes
to better follow the common Netlink attribute usage.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 87e7156..e6ce0b3 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -530,197 +530,42 @@
}
/**
- * 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;
- }
+doi_walk_return:
rcu_read_unlock();
-
- return skb;
-
-doi_dump_failure:
- rcu_read_unlock();
- kfree(skb);
- return NULL;
+ *skip_cnt = doi_cnt;
+ return ret_val;
}
/**