From 20a1452c35425b2cef76f21f8395ef069dfddfa9 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Wed, 22 Jan 2020 00:17:51 +0100 Subject: [PATCH] netfilter: nf_tables: add nft_setelem_parse_key() Add helper function to parse the set element key netlink attribute. v4: No changes v3: New patch [sbrivio: refactor error paths and labels; use NFT_DATA_VALUE_MAXLEN instead of sizeof(*key) in helper, value can be longer than that; rebase] Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_tables_api.c | 91 +++++++++++++++++------------------ 1 file changed, 45 insertions(+), 46 deletions(-) diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 7e63b481cc86..58e3b285a3d1 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -4524,11 +4524,28 @@ static int nft_setelem_parse_flags(const struct nft_set *set, return 0; } +static int nft_setelem_parse_key(struct nft_ctx *ctx, struct nft_set *set, + struct nft_data *key, struct nlattr *attr) +{ + struct nft_data_desc desc; + int err; + + err = nft_data_init(ctx, key, NFT_DATA_VALUE_MAXLEN, &desc, attr); + if (err < 0) + return err; + + if (desc.type != NFT_DATA_VALUE || desc.len != set->klen) { + nft_data_release(key, desc.type); + return -EINVAL; + } + + return 0; +} + static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set, const struct nlattr *attr) { struct nlattr *nla[NFTA_SET_ELEM_MAX + 1]; - struct nft_data_desc desc; struct nft_set_elem elem; struct sk_buff *skb; uint32_t flags = 0; @@ -4547,17 +4564,11 @@ static int nft_get_set_elem(struct nft_ctx *ctx, struct nft_set *set, if (err < 0) return err; - err = nft_data_init(ctx, &elem.key.val, sizeof(elem.key), &desc, - nla[NFTA_SET_ELEM_KEY]); + err = nft_setelem_parse_key(ctx, set, &elem.key.val, + nla[NFTA_SET_ELEM_KEY]); if (err < 0) return err; - err = -EINVAL; - if (desc.type != NFT_DATA_VALUE || desc.len != set->klen) { - nft_data_release(&elem.key.val, desc.type); - return err; - } - priv = set->ops->get(ctx->net, set, &elem, flags); if (IS_ERR(priv)) return PTR_ERR(priv); @@ -4756,13 +4767,13 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, { struct nlattr *nla[NFTA_SET_ELEM_MAX + 1]; u8 genmask = nft_genmask_next(ctx->net); - struct nft_data_desc d1, d2; struct nft_set_ext_tmpl tmpl; struct nft_set_ext *ext, *ext2; struct nft_set_elem elem; struct nft_set_binding *binding; struct nft_object *obj = NULL; struct nft_userdata *udata; + struct nft_data_desc desc; struct nft_data data; enum nft_registers dreg; struct nft_trans *trans; @@ -4828,15 +4839,12 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, return err; } - err = nft_data_init(ctx, &elem.key.val, sizeof(elem.key), &d1, - nla[NFTA_SET_ELEM_KEY]); + err = nft_setelem_parse_key(ctx, set, &elem.key.val, + nla[NFTA_SET_ELEM_KEY]); if (err < 0) goto err1; - err = -EINVAL; - if (d1.type != NFT_DATA_VALUE || d1.len != set->klen) - goto err2; - nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, d1.len); + nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, set->klen); if (timeout > 0) { nft_set_ext_add(&tmpl, NFT_SET_EXT_EXPIRATION); if (timeout != set->timeout) @@ -4859,13 +4867,13 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, } if (nla[NFTA_SET_ELEM_DATA] != NULL) { - err = nft_data_init(ctx, &data, sizeof(data), &d2, + err = nft_data_init(ctx, &data, sizeof(data), &desc, nla[NFTA_SET_ELEM_DATA]); if (err < 0) goto err2; err = -EINVAL; - if (set->dtype != NFT_DATA_VERDICT && d2.len != set->dlen) + if (set->dtype != NFT_DATA_VERDICT && desc.len != set->dlen) goto err3; dreg = nft_type_to_reg(set->dtype); @@ -4882,18 +4890,18 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set, err = nft_validate_register_store(&bind_ctx, dreg, &data, - d2.type, d2.len); + desc.type, desc.len); if (err < 0) goto err3; - if (d2.type == NFT_DATA_VERDICT && + if (desc.type == NFT_DATA_VERDICT && (data.verdict.code == NFT_GOTO || data.verdict.code == NFT_JUMP)) nft_validate_state_update(ctx->net, NFT_VALIDATE_NEED); } - nft_set_ext_add_length(&tmpl, NFT_SET_EXT_DATA, d2.len); + nft_set_ext_add_length(&tmpl, NFT_SET_EXT_DATA, desc.len); } /* The full maximum length of userdata can exceed the maximum @@ -4976,9 +4984,9 @@ err4: kfree(elem.priv); err3: if (nla[NFTA_SET_ELEM_DATA] != NULL) - nft_data_release(&data, d2.type); + nft_data_release(&data, desc.type); err2: - nft_data_release(&elem.key.val, d1.type); + nft_data_release(&elem.key.val, NFT_DATA_VALUE); err1: return err; } @@ -5074,7 +5082,6 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, { struct nlattr *nla[NFTA_SET_ELEM_MAX + 1]; struct nft_set_ext_tmpl tmpl; - struct nft_data_desc desc; struct nft_set_elem elem; struct nft_set_ext *ext; struct nft_trans *trans; @@ -5085,11 +5092,10 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, err = nla_parse_nested_deprecated(nla, NFTA_SET_ELEM_MAX, attr, nft_set_elem_policy, NULL); if (err < 0) - goto err1; + return err; - err = -EINVAL; if (nla[NFTA_SET_ELEM_KEY] == NULL) - goto err1; + return -EINVAL; nft_set_ext_prepare(&tmpl); @@ -5099,37 +5105,31 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, if (flags != 0) nft_set_ext_add(&tmpl, NFT_SET_EXT_FLAGS); - err = nft_data_init(ctx, &elem.key.val, sizeof(elem.key), &desc, - nla[NFTA_SET_ELEM_KEY]); + err = nft_setelem_parse_key(ctx, set, &elem.key.val, + nla[NFTA_SET_ELEM_KEY]); if (err < 0) - goto err1; + return err; - err = -EINVAL; - if (desc.type != NFT_DATA_VALUE || desc.len != set->klen) - goto err2; - - nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, desc.len); + nft_set_ext_add_length(&tmpl, NFT_SET_EXT_KEY, set->klen); err = -ENOMEM; elem.priv = nft_set_elem_init(set, &tmpl, elem.key.val.data, NULL, 0, 0, GFP_KERNEL); if (elem.priv == NULL) - goto err2; + goto fail_elem; ext = nft_set_elem_ext(set, elem.priv); if (flags) *nft_set_ext_flags(ext) = flags; trans = nft_trans_elem_alloc(ctx, NFT_MSG_DELSETELEM, set); - if (trans == NULL) { - err = -ENOMEM; - goto err3; - } + if (trans == NULL) + goto fail_trans; priv = set->ops->deactivate(ctx->net, set, &elem); if (priv == NULL) { err = -ENOENT; - goto err4; + goto fail_ops; } kfree(elem.priv); elem.priv = priv; @@ -5140,13 +5140,12 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set, list_add_tail(&trans->list, &ctx->net->nft.commit_list); return 0; -err4: +fail_ops: kfree(trans); -err3: +fail_trans: kfree(elem.priv); -err2: - nft_data_release(&elem.key.val, desc.type); -err1: +fail_elem: + nft_data_release(&elem.key.val, NFT_DATA_VALUE); return err; }