[PATCH net 3/7] netfilter: nf_tables: add function to create set stateful expressions
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: 2023-01-02 16:40:44
Also in:
netfilter-devel
Subsystem:
netfilter, networking [general], the rest · Maintainers:
Pablo Neira Ayuso, Florian Westphal, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Add a helper function to allocate and initialize the stateful expressions that are defined in a set. This patch allows to reuse this code from the set update path, to check that type of the update matches the existing set in the kernel. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> --- net/netfilter/nf_tables_api.c | 106 ++++++++++++++++++++++------------ 1 file changed, 68 insertions(+), 38 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 1deecc1a6c00..b9b0ae29f5f6 100644
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c@@ -4388,6 +4388,59 @@ static int nf_tables_set_desc_parse(struct nft_set_desc *desc, return err; } +static int nft_set_expr_alloc(struct nft_ctx *ctx, struct nft_set *set, + const struct nlattr * const *nla, + struct nft_expr **exprs, int *num_exprs, + u32 flags) +{ + struct nft_expr *expr; + int err, i; + + if (nla[NFTA_SET_EXPR]) { + expr = nft_set_elem_expr_alloc(ctx, set, nla[NFTA_SET_EXPR]); + if (IS_ERR(expr)) { + err = PTR_ERR(expr); + goto err_set_expr_alloc; + } + exprs[0] = expr; + (*num_exprs)++; + } else if (nla[NFTA_SET_EXPRESSIONS]) { + struct nlattr *tmp; + int left; + + if (!(flags & NFT_SET_EXPR)) { + err = -EINVAL; + goto err_set_expr_alloc; + } + i = 0; + nla_for_each_nested(tmp, nla[NFTA_SET_EXPRESSIONS], left) { + if (i == NFT_SET_EXPR_MAX) { + err = -E2BIG; + goto err_set_expr_alloc; + } + if (nla_type(tmp) != NFTA_LIST_ELEM) { + err = -EINVAL; + goto err_set_expr_alloc; + } + expr = nft_set_elem_expr_alloc(ctx, set, tmp); + if (IS_ERR(expr)) { + err = PTR_ERR(expr); + goto err_set_expr_alloc; + } + exprs[i++] = expr; + (*num_exprs)++; + } + } + + return 0; + +err_set_expr_alloc: + for (i = 0; i < *num_exprs; i++) + nft_expr_destroy(ctx, exprs[i]); + + return err; +} + static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, const struct nlattr * const nla[]) {
@@ -4395,7 +4448,6 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, u8 genmask = nft_genmask_next(info->net); u8 family = info->nfmsg->nfgen_family; const struct nft_set_ops *ops; - struct nft_expr *expr = NULL; struct net *net = info->net; struct nft_set_desc desc; struct nft_table *table;
@@ -4403,6 +4455,7 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, struct nft_set *set; struct nft_ctx ctx; size_t alloc_size; + int num_exprs = 0; char *name; int err, i; u16 udlen;
@@ -4529,6 +4582,8 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, return PTR_ERR(set); } } else { + struct nft_expr *exprs[NFT_SET_EXPR_MAX] = {}; + if (info->nlh->nlmsg_flags & NLM_F_EXCL) { NL_SET_BAD_ATTR(extack, nla[NFTA_SET_NAME]); return -EEXIST;
@@ -4536,6 +4591,13 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, if (info->nlh->nlmsg_flags & NLM_F_REPLACE) return -EOPNOTSUPP; + err = nft_set_expr_alloc(&ctx, set, nla, exprs, &num_exprs, flags); + if (err < 0) + return err; + + for (i = 0; i < num_exprs; i++) + nft_expr_destroy(&ctx, exprs[i]); + return 0; }
@@ -4603,43 +4665,11 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, if (err < 0) goto err_set_init; - if (nla[NFTA_SET_EXPR]) { - expr = nft_set_elem_expr_alloc(&ctx, set, nla[NFTA_SET_EXPR]); - if (IS_ERR(expr)) { - err = PTR_ERR(expr); - goto err_set_expr_alloc; - } - set->exprs[0] = expr; - set->num_exprs++; - } else if (nla[NFTA_SET_EXPRESSIONS]) { - struct nft_expr *expr; - struct nlattr *tmp; - int left; - - if (!(flags & NFT_SET_EXPR)) { - err = -EINVAL; - goto err_set_expr_alloc; - } - i = 0; - nla_for_each_nested(tmp, nla[NFTA_SET_EXPRESSIONS], left) { - if (i == NFT_SET_EXPR_MAX) { - err = -E2BIG; - goto err_set_expr_alloc; - } - if (nla_type(tmp) != NFTA_LIST_ELEM) { - err = -EINVAL; - goto err_set_expr_alloc; - } - expr = nft_set_elem_expr_alloc(&ctx, set, tmp); - if (IS_ERR(expr)) { - err = PTR_ERR(expr); - goto err_set_expr_alloc; - } - set->exprs[i++] = expr; - set->num_exprs++; - } - } + err = nft_set_expr_alloc(&ctx, set, nla, set->exprs, &num_exprs, flags); + if (err < 0) + goto err_set_destroy; + set->num_exprs = num_exprs; set->handle = nf_tables_alloc_handle(table); err = nft_trans_set_add(&ctx, NFT_MSG_NEWSET, set);
@@ -4653,7 +4683,7 @@ static int nf_tables_newset(struct sk_buff *skb, const struct nfnl_info *info, err_set_expr_alloc: for (i = 0; i < set->num_exprs; i++) nft_expr_destroy(&ctx, set->exprs[i]); - +err_set_destroy: ops->destroy(set); err_set_init: kfree(set->name);
--
2.30.2