diff options
| -rw-r--r-- | include/net/netfilter/nf_tables_core.h | 9 | ||||
| -rw-r--r-- | include/uapi/linux/netfilter/nf_tables.h | 17 | ||||
| -rw-r--r-- | net/netfilter/nft_payload.c | 135 |
3 files changed, 155 insertions, 6 deletions
diff --git a/include/net/netfilter/nf_tables_core.h b/include/net/netfilter/nf_tables_core.h index c6f400cfaac8..4ff5424909aa 100644 --- a/include/net/netfilter/nf_tables_core.h +++ b/include/net/netfilter/nf_tables_core.h @@ -47,6 +47,15 @@ struct nft_payload { enum nft_registers dreg:8; }; +struct nft_payload_set { + enum nft_payload_bases base:8; + u8 offset; + u8 len; + enum nft_registers sreg:8; + u8 csum_type; + u8 csum_offset; +}; + extern const struct nft_expr_ops nft_payload_fast_ops; int nft_payload_module_init(void); diff --git a/include/uapi/linux/netfilter/nf_tables.h b/include/uapi/linux/netfilter/nf_tables.h index d8c8a7c9d88a..5f3ececf84b3 100644 --- a/include/uapi/linux/netfilter/nf_tables.h +++ b/include/uapi/linux/netfilter/nf_tables.h @@ -598,12 +598,26 @@ enum nft_payload_bases { }; /** + * enum nft_payload_csum_types - nf_tables payload expression checksum types + * + * @NFT_PAYLOAD_CSUM_NONE: no checksumming + * @NFT_PAYLOAD_CSUM_INET: internet checksum (RFC 791) + */ +enum nft_payload_csum_types { + NFT_PAYLOAD_CSUM_NONE, + NFT_PAYLOAD_CSUM_INET, +}; + +/** * enum nft_payload_attributes - nf_tables payload expression netlink attributes * * @NFTA_PAYLOAD_DREG: destination register to load data into (NLA_U32: nft_registers) * @NFTA_PAYLOAD_BASE: payload base (NLA_U32: nft_payload_bases) * @NFTA_PAYLOAD_OFFSET: payload offset relative to base (NLA_U32) * @NFTA_PAYLOAD_LEN: payload length (NLA_U32) + * @NFTA_PAYLOAD_SREG: source register to load data from (NLA_U32: nft_registers) + * @NFTA_PAYLOAD_CSUM_TYPE: checksum type (NLA_U32) + * @NFTA_PAYLOAD_CSUM_OFFSET: checksum offset relative to base (NLA_U32) */ enum nft_payload_attributes { NFTA_PAYLOAD_UNSPEC, @@ -611,6 +625,9 @@ enum nft_payload_attributes { NFTA_PAYLOAD_BASE, NFTA_PAYLOAD_OFFSET, NFTA_PAYLOAD_LEN, + NFTA_PAYLOAD_SREG, + NFTA_PAYLOAD_CSUM_TYPE, + NFTA_PAYLOAD_CSUM_OFFSET, __NFTA_PAYLOAD_MAX }; #define NFTA_PAYLOAD_MAX (__NFTA_PAYLOAD_MAX - 1) diff --git a/net/netfilter/nft_payload.c b/net/netfilter/nft_payload.c index 09b4b07eb676..12cd4bf16d17 100644 --- a/net/netfilter/nft_payload.c +++ b/net/netfilter/nft_payload.c @@ -107,10 +107,13 @@ err: } static const struct nla_policy nft_payload_policy[NFTA_PAYLOAD_MAX + 1] = { - [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 }, - [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 }, - [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 }, - [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 }, + [NFTA_PAYLOAD_SREG] = { .type = NLA_U32 }, + [NFTA_PAYLOAD_DREG] = { .type = NLA_U32 }, + [NFTA_PAYLOAD_BASE] = { .type = NLA_U32 }, + [NFTA_PAYLOAD_OFFSET] = { .type = NLA_U32 }, + [NFTA_PAYLOAD_LEN] = { .type = NLA_U32 }, + [NFTA_PAYLOAD_CSUM_TYPE] = { .type = NLA_U32 }, + [NFTA_PAYLOAD_CSUM_OFFSET] = { .type = NLA_U32 }, }; static int nft_payload_init(const struct nft_ctx *ctx, @@ -160,6 +163,118 @@ const struct nft_expr_ops nft_payload_fast_ops = { .dump = nft_payload_dump, }; +static void nft_payload_set_eval(const struct nft_expr *expr, + struct nft_regs *regs, + const struct nft_pktinfo *pkt) +{ + const struct nft_payload_set *priv = nft_expr_priv(expr); + struct sk_buff *skb = pkt->skb; + const u32 *src = ®s->data[priv->sreg]; + int offset, csum_offset; + __wsum fsum, tsum; + __sum16 sum; + + switch (priv->base) { + case NFT_PAYLOAD_LL_HEADER: + if (!skb_mac_header_was_set(skb)) + goto err; + offset = skb_mac_header(skb) - skb->data; + break; + case NFT_PAYLOAD_NETWORK_HEADER: + offset = skb_network_offset(skb); + break; + case NFT_PAYLOAD_TRANSPORT_HEADER: + offset = pkt->xt.thoff; + break; + default: + BUG(); + } + + csum_offset = offset + priv->csum_offset; + offset += priv->offset; + + if (priv->csum_type == NFT_PAYLOAD_CSUM_INET && + (priv->base != NFT_PAYLOAD_TRANSPORT_HEADER || + skb->ip_summed != CHECKSUM_PARTIAL)) { + if (skb_copy_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) + goto err; + + fsum = skb_checksum(skb, offset, priv->len, 0); + tsum = csum_partial(src, priv->len, 0); + sum = csum_fold(csum_add(csum_sub(~csum_unfold(sum), fsum), + tsum)); + if (sum == 0) + sum = CSUM_MANGLED_0; + + if (!skb_make_writable(skb, csum_offset + sizeof(sum)) || + skb_store_bits(skb, csum_offset, &sum, sizeof(sum)) < 0) + goto err; + } + + if (!skb_make_writable(skb, max(offset + priv->len, 0)) || + skb_store_bits(skb, offset, src, priv->len) < 0) + goto err; + + return; +err: + regs->verdict.code = NFT_BREAK; +} + +static int nft_payload_set_init(const struct nft_ctx *ctx, + const struct nft_expr *expr, + const struct nlattr * const tb[]) +{ + struct nft_payload_set *priv = nft_expr_priv(expr); + + priv->base = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_BASE])); + priv->offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); + priv->len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); + priv->sreg = nft_parse_register(tb[NFTA_PAYLOAD_SREG]); + + if (tb[NFTA_PAYLOAD_CSUM_TYPE]) + priv->csum_type = + ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_TYPE])); + if (tb[NFTA_PAYLOAD_CSUM_OFFSET]) + priv->csum_offset = + ntohl(nla_get_be32(tb[NFTA_PAYLOAD_CSUM_OFFSET])); + + switch (priv->csum_type) { + case NFT_PAYLOAD_CSUM_NONE: + case NFT_PAYLOAD_CSUM_INET: + break; + default: + return -EOPNOTSUPP; + } + + return nft_validate_register_load(priv->sreg, priv->len); +} + +static int nft_payload_set_dump(struct sk_buff *skb, const struct nft_expr *expr) +{ + const struct nft_payload_set *priv = nft_expr_priv(expr); + + if (nft_dump_register(skb, NFTA_PAYLOAD_SREG, priv->sreg) || + nla_put_be32(skb, NFTA_PAYLOAD_BASE, htonl(priv->base)) || + nla_put_be32(skb, NFTA_PAYLOAD_OFFSET, htonl(priv->offset)) || + nla_put_be32(skb, NFTA_PAYLOAD_LEN, htonl(priv->len)) || + nla_put_be32(skb, NFTA_PAYLOAD_CSUM_TYPE, htonl(priv->csum_type)) || + nla_put_be32(skb, NFTA_PAYLOAD_CSUM_OFFSET, + htonl(priv->csum_offset))) + goto nla_put_failure; + return 0; + +nla_put_failure: + return -1; +} + +static const struct nft_expr_ops nft_payload_set_ops = { + .type = &nft_payload_type, + .size = NFT_EXPR_SIZE(sizeof(struct nft_payload_set)), + .eval = nft_payload_set_eval, + .init = nft_payload_set_init, + .dump = nft_payload_set_dump, +}; + static const struct nft_expr_ops * nft_payload_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[]) @@ -167,8 +282,7 @@ nft_payload_select_ops(const struct nft_ctx *ctx, enum nft_payload_bases base; unsigned int offset, len; - if (tb[NFTA_PAYLOAD_DREG] == NULL || - tb[NFTA_PAYLOAD_BASE] == NULL || + if (tb[NFTA_PAYLOAD_BASE] == NULL || tb[NFTA_PAYLOAD_OFFSET] == NULL || tb[NFTA_PAYLOAD_LEN] == NULL) return ERR_PTR(-EINVAL); @@ -183,6 +297,15 @@ nft_payload_select_ops(const struct nft_ctx *ctx, return ERR_PTR(-EOPNOTSUPP); } + if (tb[NFTA_PAYLOAD_SREG] != NULL) { + if (tb[NFTA_PAYLOAD_DREG] != NULL) + return ERR_PTR(-EINVAL); + return &nft_payload_set_ops; + } + + if (tb[NFTA_PAYLOAD_DREG] == NULL) + return ERR_PTR(-EINVAL); + offset = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_OFFSET])); len = ntohl(nla_get_be32(tb[NFTA_PAYLOAD_LEN])); |