From fcd48280643e92ec6cb29a04e9079dd7b6b5bfef Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Mon, 25 Sep 2006 15:56:09 -0700 Subject: [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 Signed-off-by: David S. Miller --- net/netlabel/netlabel_domainhash.c | 183 ++++++++----------------------------- 1 file changed, 37 insertions(+), 146 deletions(-) (limited to 'net/netlabel/netlabel_domainhash.c') diff --git a/net/netlabel/netlabel_domainhash.c b/net/netlabel/netlabel_domainhash.c index 0489a1378101..f56d7a8ac7b7 100644 --- a/net/netlabel/netlabel_domainhash.c +++ b/net/netlabel/netlabel_domainhash.c @@ -354,160 +354,51 @@ 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; } -- cgit v1.2.3