From ebddf1a8d78aa3436353fae75c4396e50cb2d6cf Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Tue, 26 May 2015 18:41:20 +0200 Subject: [PATCH] netfilter: nf_tables: allow to bind table to net_device This patch adds the internal NFT_AF_NEEDS_DEV flag to indicate that you must attach this table to a net_device. This change is required by the follow up patch that introduces the new netdev table. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 8 +++++ include/uapi/linux/netfilter/nf_tables.h | 2 ++ net/netfilter/nf_tables_api.c | 46 +++++++++++++++++++++--- 3 files changed, 51 insertions(+), 5 deletions(-) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index e6bcf55dcf20..3d6f48ca40a7 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -819,6 +819,7 @@ unsigned int nft_do_chain(struct nft_pktinfo *pkt, * @use: number of chain references to this table * @flags: table flag (see enum nft_table_flags) * @name: name of the table + * @dev: this table is bound to this device (if any) */ struct nft_table { struct list_head list; @@ -828,6 +829,11 @@ struct nft_table { u32 use; u16 flags; char name[NFT_TABLE_MAXNAMELEN]; + struct net_device *dev; +}; + +enum nft_af_flags { + NFT_AF_NEEDS_DEV = (1 << 0), }; /** @@ -838,6 +844,7 @@ struct nft_table { * @nhooks: number of hooks in this family * @owner: module owner * @tables: used internally + * @flags: family flags * @nops: number of hook ops in this family * @hook_ops_init: initialization function for chain hook ops * @hooks: hookfn overrides for packet validation @@ -848,6 +855,7 @@ struct nft_af_info { unsigned int nhooks; struct module *owner; struct list_head tables; + u32 flags; unsigned int nops; void (*hook_ops_init)(struct nf_hook_ops *, unsigned int); diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index 5fa1cd04762e..89a671e0f5e7 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -146,12 +146,14 @@ enum nft_table_flags { * @NFTA_TABLE_NAME: name of the table (NLA_STRING) * @NFTA_TABLE_FLAGS: bitmask of enum nft_table_flags (NLA_U32) * @NFTA_TABLE_USE: number of chains in this table (NLA_U32) + * @NFTA_TABLE_DEV: net device name (NLA_STRING) */ enum nft_table_attributes { NFTA_TABLE_UNSPEC, NFTA_TABLE_NAME, NFTA_TABLE_FLAGS, NFTA_TABLE_USE, + NFTA_TABLE_DEV, __NFTA_TABLE_MAX }; #define NFTA_TABLE_MAX (__NFTA_TABLE_MAX - 1) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index ad9d11fb29fd..2fd4e99dd074 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -399,6 +399,8 @@ static const struct nla_policy nft_table_policy[NFTA_TABLE_MAX + 1] = { [NFTA_TABLE_NAME] = { .type = NLA_STRING, .len = NFT_TABLE_MAXNAMELEN - 1 }, [NFTA_TABLE_FLAGS] = { .type = NLA_U32 }, + [NFTA_TABLE_DEV] = { .type = NLA_STRING, + .len = IFNAMSIZ - 1 }, }; static int nf_tables_fill_table_info(struct sk_buff *skb, struct net *net, @@ -423,6 +425,10 @@ static int nf_tables_fill_table_info(struct sk_buff *skb, struct net *net, nla_put_be32(skb, NFTA_TABLE_USE, htonl(table->use))) goto nla_put_failure; + if (table->dev && + nla_put_string(skb, NFTA_TABLE_DEV, table->dev->name)) + goto nla_put_failure; + nlmsg_end(skb, nlh); return 0; @@ -608,6 +614,11 @@ static int nf_tables_updtable(struct nft_ctx *ctx) if (flags == ctx->table->flags) return 0; + if ((ctx->afi->flags & NFT_AF_NEEDS_DEV) && + ctx->nla[NFTA_TABLE_DEV] && + nla_strcmp(ctx->nla[NFTA_TABLE_DEV], ctx->table->dev->name)) + return -EOPNOTSUPP; + trans = nft_trans_alloc(ctx, NFT_MSG_NEWTABLE, sizeof(struct nft_trans_table)); if (trans == NULL) @@ -645,6 +656,7 @@ static int nf_tables_newtable(struct sock *nlsk, struct sk_buff *skb, struct nft_table *table; struct net *net = sock_net(skb->sk); int family = nfmsg->nfgen_family; + struct net_device *dev = NULL; u32 flags = 0; struct nft_ctx ctx; int err; @@ -679,30 +691,50 @@ static int nf_tables_newtable(struct sock *nlsk, struct sk_buff *skb, return -EINVAL; } + if (afi->flags & NFT_AF_NEEDS_DEV) { + char ifname[IFNAMSIZ]; + + if (!nla[NFTA_TABLE_DEV]) + return -EOPNOTSUPP; + + nla_strlcpy(ifname, nla[NFTA_TABLE_DEV], IFNAMSIZ); + dev = dev_get_by_name(net, ifname); + if (!dev) + return -ENOENT; + } else if (nla[NFTA_TABLE_DEV]) { + return -EOPNOTSUPP; + } + + err = -EAFNOSUPPORT; if (!try_module_get(afi->owner)) - return -EAFNOSUPPORT; + goto err1; err = -ENOMEM; table = kzalloc(sizeof(*table), GFP_KERNEL); if (table == NULL) - goto err1; + goto err2; nla_strlcpy(table->name, name, NFT_TABLE_MAXNAMELEN); INIT_LIST_HEAD(&table->chains); INIT_LIST_HEAD(&table->sets); table->flags = flags; + table->dev = dev; nft_ctx_init(&ctx, skb, nlh, afi, table, NULL, nla); err = nft_trans_table_add(&ctx, NFT_MSG_NEWTABLE); if (err < 0) - goto err2; + goto err3; list_add_tail_rcu(&table->list, &afi->tables); return 0; -err2: +err3: kfree(table); -err1: +err2: module_put(afi->owner); +err1: + if (dev != NULL) + dev_put(dev); + return err; } @@ -806,6 +838,9 @@ static void nf_tables_table_destroy(struct nft_ctx *ctx) { BUG_ON(ctx->table->use > 0); + if (ctx->table->dev) + dev_put(ctx->table->dev); + kfree(ctx->table); module_put(ctx->afi->owner); } @@ -1361,6 +1396,7 @@ static int nf_tables_newchain(struct sock *nlsk, struct sk_buff *skb, ops->priority = priority; ops->priv = chain; ops->hook = afi->hooks[ops->hooknum]; + ops->dev = table->dev; if (hookfn) ops->hook = hookfn; if (afi->hook_ops_init) -- 2.20.1