From 4386b921857793440ebd4db3d6b70639149c7074 Mon Sep 17 00:00:00 2001 From: Sriram Yagnaraman Date: Fri, 24 Feb 2023 10:52:51 +0100 Subject: [PATCH] netfilter: bridge: introduce broute meta statement nftables equivalent for ebtables -t broute. Implement broute meta statement to set br_netfilter_broute flag in skb to force a packet to be routed instead of being bridged. Signed-off-by: Sriram Yagnaraman Signed-off-by: Florian Westphal --- include/uapi/linux/netfilter/nf_tables.h | 2 + net/bridge/netfilter/nft_meta_bridge.c | 71 +++++++++++++++++++++++- 2 files changed, 70 insertions(+), 3 deletions(-) diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index ff677f3a6cad..9c6f02c26054 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -931,6 +931,7 @@ enum nft_exthdr_attributes { * @NFT_META_TIME_HOUR: hour of day (in seconds) * @NFT_META_SDIF: slave device interface index * @NFT_META_SDIFNAME: slave device interface name + * @NFT_META_BRI_BROUTE: packet br_netfilter_broute bit */ enum nft_meta_keys { NFT_META_LEN, @@ -969,6 +970,7 @@ enum nft_meta_keys { NFT_META_TIME_HOUR, NFT_META_SDIF, NFT_META_SDIFNAME, + NFT_META_BRI_BROUTE, __NFT_META_IIFTYPE, }; diff --git a/net/bridge/netfilter/nft_meta_bridge.c b/net/bridge/netfilter/nft_meta_bridge.c index c3ecd77e25cb..bd4d1b4d745f 100644 --- a/net/bridge/netfilter/nft_meta_bridge.c +++ b/net/bridge/netfilter/nft_meta_bridge.c @@ -8,6 +8,9 @@ #include #include #include +#include /* NF_BR_PRE_ROUTING */ + +#include "../br_private.h" static const struct net_device * nft_meta_get_bridge(const struct net_device *dev) @@ -102,6 +105,50 @@ static const struct nft_expr_ops nft_meta_bridge_get_ops = { .reduce = nft_meta_get_reduce, }; +static void nft_meta_bridge_set_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_meta *meta = nft_expr_priv(expr); + u32 *sreg = ®s->data[meta->sreg]; + struct sk_buff *skb = pkt->skb; + u8 value8; + + switch (meta->key) { + case NFT_META_BRI_BROUTE: + value8 = nft_reg_load8(sreg); + BR_INPUT_SKB_CB(skb)->br_netfilter_broute = !!value8; + break; + default: + nft_meta_set_eval(expr, regs, pkt); + } +} + +static int nft_meta_bridge_set_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_meta *priv = nft_expr_priv(expr); + unsigned int len; + int err; + + priv->key = ntohl(nla_get_be32(tb[NFTA_META_KEY])); + switch (priv->key) { + case NFT_META_BRI_BROUTE: + len = sizeof(u8); + break; + default: + return nft_meta_set_init(ctx, expr, tb); + } + + priv->len = len; + err = nft_parse_register_load(tb[NFTA_META_SREG], &priv->sreg, len); + if (err < 0) + return err; + + return 0; +} + static bool nft_meta_bridge_set_reduce(struct nft_regs_track *track, const struct nft_expr *expr) { @@ -120,15 +167,33 @@ static bool nft_meta_bridge_set_reduce(struct nft_regs_track *track, return false; } +static int nft_meta_bridge_set_validate(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nft_data **data) +{ + struct nft_meta *priv = nft_expr_priv(expr); + unsigned int hooks; + + switch (priv->key) { + case NFT_META_BRI_BROUTE: + hooks = 1 << NF_BR_PRE_ROUTING; + break; + default: + return nft_meta_set_validate(ctx, expr, data); + } + + return nft_chain_validate_hooks(ctx->chain, hooks); +} + static const struct nft_expr_ops nft_meta_bridge_set_ops = { .type = &nft_meta_bridge_type, .size = NFT_EXPR_SIZE(sizeof(struct nft_meta)), - .eval = nft_meta_set_eval, - .init = nft_meta_set_init, + .eval = nft_meta_bridge_set_eval, + .init = nft_meta_bridge_set_init, .destroy = nft_meta_set_destroy, .dump = nft_meta_set_dump, .reduce = nft_meta_bridge_set_reduce, - .validate = nft_meta_set_validate, + .validate = nft_meta_bridge_set_validate, }; static const struct nft_expr_ops *