From a9fea2a3c3cf7a09b7f4302489f535477ead67d2 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Mon, 28 Nov 2016 00:06:11 +0100 Subject: [PATCH] netfilter: nf_tables: allow to filter stateful object dumps by type This patch adds the netlink code to filter out dump of stateful objects, through the NFTA_OBJ_TYPE netlink attribute. Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 50 +++++++++++++++++++++++++++++++++++ 1 file changed, 50 insertions(+) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index b4db5bf4c135..b04d4ee1d533 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -4183,12 +4183,18 @@ nla_put_failure: return -1; } +struct nft_obj_filter { + char table[NFT_OBJ_MAXNAMELEN]; + u32 type; +}; + static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) { const struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh); const struct nft_af_info *afi; const struct nft_table *table; unsigned int idx = 0, s_idx = cb->args[0]; + struct nft_obj_filter *filter = cb->data; struct net *net = sock_net(skb->sk); int family = nfmsg->nfgen_family; struct nft_object *obj; @@ -4213,6 +4219,13 @@ static int nf_tables_dump_obj(struct sk_buff *skb, struct netlink_callback *cb) if (idx > s_idx) memset(&cb->args[1], 0, sizeof(cb->args) - sizeof(cb->args[0])); + if (filter->table[0] && + strcmp(filter->table, table->name)) + goto cont; + if (filter->type != NFT_OBJECT_UNSPEC && + obj->type->type != filter->type) + goto cont; + if (nf_tables_fill_obj_info(skb, net, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NFT_MSG_NEWOBJ, @@ -4233,6 +4246,31 @@ done: return skb->len; } +static int nf_tables_dump_obj_done(struct netlink_callback *cb) +{ + kfree(cb->data); + + return 0; +} + +static struct nft_obj_filter * +nft_obj_filter_alloc(const struct nlattr * const nla[]) +{ + struct nft_obj_filter *filter; + + filter = kzalloc(sizeof(*filter), GFP_KERNEL); + if (!filter) + return ERR_PTR(-ENOMEM); + + if (nla[NFTA_OBJ_TABLE]) + nla_strlcpy(filter->table, nla[NFTA_OBJ_TABLE], + NFT_TABLE_MAXNAMELEN); + if (nla[NFTA_OBJ_TYPE]) + filter->type = ntohl(nla_get_be32(nla[NFTA_OBJ_TYPE])); + + return filter; +} + static int nf_tables_getobj(struct net *net, struct sock *nlsk, struct sk_buff *skb, const struct nlmsghdr *nlh, const struct nlattr * const nla[]) @@ -4251,7 +4289,19 @@ static int nf_tables_getobj(struct net *net, struct sock *nlsk, if (nlh->nlmsg_flags & NLM_F_DUMP) { struct netlink_dump_control c = { .dump = nf_tables_dump_obj, + .done = nf_tables_dump_obj_done, }; + + if (nla[NFTA_OBJ_TABLE] || + nla[NFTA_OBJ_TYPE]) { + struct nft_obj_filter *filter; + + filter = nft_obj_filter_alloc(nla); + if (IS_ERR(filter)) + return -ENOMEM; + + c.data = filter; + } return netlink_dump_start(nlsk, skb, nlh, &c); } -- 2.39.5