netfilter: nf_tables: support variable sized data in nft_data_init()

Add a size argument to nft_data_init() and pass in the available space.
This will be used by the following patches to support variable sized
set element data.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h
index 1f9b848c778c8c115ee5e9ad26bed7a614875985..160577bf0f0ac5c11fa1ecc5c444949a098ef4e8 100644 (file)
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -110,7 +110,8 @@ struct nft_data_desc {
        unsigned int                    len;
 };
 
-int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data,
+int nft_data_init(const struct nft_ctx *ctx,
+                 struct nft_data *data, unsigned int size,
                  struct nft_data_desc *desc, const struct nlattr *nla);
 void nft_data_uninit(const struct nft_data *data, enum nft_data_types type);
 int nft_data_dump(struct sk_buff *skb, int attr, const struct nft_data *data,

diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c
index 03faf76ce3b868a17d16db9d038593349633f1d6..2b3f88f4c70fc8d44c7173ec47f28e5b637a3b6f 100644 (file)
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -3299,7 +3299,8 @@ static int nft_add_set_elem(struct nft_ctx *ctx, struct nft_set *set,
                timeout = set->timeout;
        }
 
-       err = nft_data_init(ctx, &elem.key, &d1, nla[NFTA_SET_ELEM_KEY]);
+       err = nft_data_init(ctx, &elem.key, sizeof(elem.key), &d1,
+                           nla[NFTA_SET_ELEM_KEY]);
        if (err < 0)
                goto err1;
        err = -EINVAL;
@@ -3314,7 +3315,8 @@ 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, &d2, nla[NFTA_SET_ELEM_DATA]);
+               err = nft_data_init(ctx, &data, sizeof(data), &d2,
+                                   nla[NFTA_SET_ELEM_DATA]);
                if (err < 0)
                        goto err2;
 
@@ -3458,7 +3460,8 @@ static int nft_del_setelem(struct nft_ctx *ctx, struct nft_set *set,
        if (nla[NFTA_SET_ELEM_KEY] == NULL)
                goto err1;
 
-       err = nft_data_init(ctx, &elem.key, &desc, nla[NFTA_SET_ELEM_KEY]);
+       err = nft_data_init(ctx, &elem.key, sizeof(elem.key), &desc,
+                           nla[NFTA_SET_ELEM_KEY]);
        if (err < 0)
                goto err1;
 
@@ -4339,7 +4342,8 @@ nla_put_failure:
        return -1;
 }
 
-static int nft_value_init(const struct nft_ctx *ctx, struct nft_data *data,
+static int nft_value_init(const struct nft_ctx *ctx,
+                         struct nft_data *data, unsigned int size,
                          struct nft_data_desc *desc, const struct nlattr *nla)
 {
        unsigned int len;
@@ -4347,10 +4351,10 @@ static int nft_value_init(const struct nft_ctx *ctx, struct nft_data *data,
        len = nla_len(nla);
        if (len == 0)
                return -EINVAL;
-       if (len > sizeof(data->data))
+       if (len > size)
                return -EOVERFLOW;
 
-       nla_memcpy(data->data, nla, sizeof(data->data));
+       nla_memcpy(data->data, nla, len);
        desc->type = NFT_DATA_VALUE;
        desc->len  = len;
        return 0;
@@ -4363,8 +4367,7 @@ static int nft_value_dump(struct sk_buff *skb, const struct nft_data *data,
 }
 
 static const struct nla_policy nft_data_policy[NFTA_DATA_MAX + 1] = {
-       [NFTA_DATA_VALUE]       = { .type = NLA_BINARY,
-                                   .len  = FIELD_SIZEOF(struct nft_data, data) },
+       [NFTA_DATA_VALUE]       = { .type = NLA_BINARY },
        [NFTA_DATA_VERDICT]     = { .type = NLA_NESTED },
 };
 
@@ -4373,6 +4376,7 @@ static const struct nla_policy nft_data_policy[NFTA_DATA_MAX + 1] = {
  *
  *     @ctx: context of the expression using the data
  *     @data: destination struct nft_data
+ *     @size: maximum data length
  *     @desc: data description
  *     @nla: netlink attribute containing data
  *
@@ -4382,7 +4386,8 @@ static const struct nla_policy nft_data_policy[NFTA_DATA_MAX + 1] = {
  *     The caller can indicate that it only wants to accept data of type
  *     NFT_DATA_VALUE by passing NULL for the ctx argument.
  */
-int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data,
+int nft_data_init(const struct nft_ctx *ctx,
+                 struct nft_data *data, unsigned int size,
                  struct nft_data_desc *desc, const struct nlattr *nla)
 {
        struct nlattr *tb[NFTA_DATA_MAX + 1];
@@ -4393,7 +4398,8 @@ int nft_data_init(const struct nft_ctx *ctx, struct nft_data *data,
                return err;
 
        if (tb[NFTA_DATA_VALUE])
-               return nft_value_init(ctx, data, desc, tb[NFTA_DATA_VALUE]);
+               return nft_value_init(ctx, data, size, desc,
+                                     tb[NFTA_DATA_VALUE]);
        if (tb[NFTA_DATA_VERDICT] && ctx != NULL)
                return nft_verdict_init(ctx, data, desc, tb[NFTA_DATA_VERDICT]);
        return -EINVAL;

diff --git a/net/netfilter/nft_bitwise.c b/net/netfilter/nft_bitwise.c
index f1a9be2aecd17a9ef2eefd26c8b0bf8c5e806ea8..d71cc18fa35daaee8e2c12cfdbee557d17daf559 100644 (file)
--- a/net/netfilter/nft_bitwise.c
+++ b/net/netfilter/nft_bitwise.c
@@ -73,13 +73,15 @@ static int nft_bitwise_init(const struct nft_ctx *ctx,
        if (err < 0)
                return err;
 
-       err = nft_data_init(NULL, &priv->mask, &d1, tb[NFTA_BITWISE_MASK]);
+       err = nft_data_init(NULL, &priv->mask, sizeof(priv->mask), &d1,
+                           tb[NFTA_BITWISE_MASK]);
        if (err < 0)
                return err;
        if (d1.len != priv->len)
                return -EINVAL;
 
-       err = nft_data_init(NULL, &priv->xor, &d2, tb[NFTA_BITWISE_XOR]);
+       err = nft_data_init(NULL, &priv->xor, sizeof(priv->xor), &d2,
+                           tb[NFTA_BITWISE_XOR]);
        if (err < 0)
                return err;
        if (d2.len != priv->len)

diff --git a/net/netfilter/nft_cmp.c b/net/netfilter/nft_cmp.c
index ffaf214dd2564eda82dfb06669db223d1bdc197b..e25b35d70e4dc8a1f63de86f112f37760c132227 100644 (file)
--- a/net/netfilter/nft_cmp.c
+++ b/net/netfilter/nft_cmp.c
@@ -75,7 +75,8 @@ static int nft_cmp_init(const struct nft_ctx *ctx, const struct nft_expr *expr,
        struct nft_data_desc desc;
        int err;
 
-       err = nft_data_init(NULL, &priv->data, &desc, tb[NFTA_CMP_DATA]);
+       err = nft_data_init(NULL, &priv->data, sizeof(priv->data), &desc,
+                           tb[NFTA_CMP_DATA]);
        BUG_ON(err < 0);
 
        priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
@@ -125,7 +126,8 @@ static int nft_cmp_fast_init(const struct nft_ctx *ctx,
        u32 mask;
        int err;
 
-       err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);
+       err = nft_data_init(NULL, &data, sizeof(data), &desc,
+                           tb[NFTA_CMP_DATA]);
        BUG_ON(err < 0);
 
        priv->sreg = nft_parse_register(tb[NFTA_CMP_SREG]);
@@ -195,7 +197,8 @@ nft_cmp_select_ops(const struct nft_ctx *ctx, const struct nlattr * const tb[])
                return ERR_PTR(-EINVAL);
        }
 
-       err = nft_data_init(NULL, &data, &desc, tb[NFTA_CMP_DATA]);
+       err = nft_data_init(NULL, &data, sizeof(data), &desc,
+                           tb[NFTA_CMP_DATA]);
        if (err < 0)
                return ERR_PTR(err);
 

diff --git a/net/netfilter/nft_immediate.c b/net/netfilter/nft_immediate.c
index 1e8e412eadaeaf95146956d277c177cfe73d70e9..db3b746858e35a008ad0668f42e6037e36e1f80e 100644 (file)
--- a/net/netfilter/nft_immediate.c
+++ b/net/netfilter/nft_immediate.c
@@ -49,7 +49,8 @@ static int nft_immediate_init(const struct nft_ctx *ctx,
            tb[NFTA_IMMEDIATE_DATA] == NULL)
                return -EINVAL;
 
-       err = nft_data_init(ctx, &priv->data, &desc, tb[NFTA_IMMEDIATE_DATA]);
+       err = nft_data_init(ctx, &priv->data, sizeof(priv->data), &desc,
+                           tb[NFTA_IMMEDIATE_DATA]);
        if (err < 0)
                return err;
        priv->dlen = desc.len;